As explained in the previous lesson, from the grammatical point of view, there are situations that you have to use たら (tara) sentence because of the regulation in Sentence 2. For example...

1. お酒を飲むと、運転してはいけません。 Xosake wo nomu to, untenshitewa ikemasen X

Meaning: You must not drive if you drink alcohol. 2. お酒を飲めば、運転してはいけません。 X

osake wo nomeba, untenshitewa ikemasen X

Meaning: You must not drive if you drink alcohol. 3. お酒を飲んだら、運転してはいけません。 O

osake wo nondara, untenshitewa ikemasen O

Meaning: You must not drive if you drink alcohol.

Example 1 above is incorrect because you cannot have expression of prohibition in Sentence 2 for と (to) sentence.

In Example 2 the subjects of both Sentence 1 and Sentence 2 are the same - あなた (anata - You). The verb 飲む (nomu - drink) in Sentence 1 is an action verb, so you cannot have expression of one's hope, wish, request, permission, prohibition, etc in Sentence 2. Since 運転してはいけません (untenshitewa ikemasen) is a prohibition, this sentence is also incorrect using ば (ba) / なら (nara) sentence.

In this case, you can only use たら (tara) sentence for the conditional sentence.

Situations When All 3 Japanese Conditional Forms Can Be Used

However, there're situations when you can use all the conditional forms - と (to) sentence, ば (ba) / なら (nara) sentence and たら (tara) sentence. For example...

1. 春になると、桜が咲きます。 Oharu ni naru to, sakura ga sakimasu O

Meaning: If Spring comes, the cherry blossom will bloom. 2. 春になれば、桜が咲きます。 O

haru ni nareba, sakura ga sakimasu O

Meaning: If Spring comes, the cherry blossom will bloom. 3. 春になったら、桜が咲きます。 O

haru ni nattara, sakura ga sakimasu O

Meaning: If Spring comes, the cherry blossom will bloom.

In Example 1 above, 桜が咲きます (sakura ga sakimasu) in Sentence 2 is not a personal intention, so と (to) sentence can be used.

In Example 2, 春になる (haru ni naru) in Sentence 1 is not an action verb. Hence, the regulation does not apply here. Therefore ば (ba) / なら (nara) sentence is also correct.

And obviously since たら (tara) sentence has no regulation, it's also correct to use it as in Example 3.

Since all the 3 Japanese conditional forms can be used here, it's natural that you'll ask how to decide which one to use? What is the situation that you should use と (to) sentence? What is the situation that you should use ば (ba) / なら (nara) sentence? And what is the situation that you should use たら (tara) sentence?

When to Use と, ば / なら and たら Sentences?

When you are constructing a sentence using Japanese conditional form, there are 2 aspects that you need to look into.

Firstly, you must look from the grammatical point of view, which means checking the sentence against the rules/regulations. If the sentence doesn't fulfill the regulations like the above example on お酒 (osake) and 運転 (unten), automatically there is no other choice but to use たら (tara) sentence.

However, for a sentence like the above example on 春 (haru) and 桜 (sakura) where you can use all the 3 Japanese conditional forms, which one do you use? In this case, you have to look into the second aspect - the conversational point of view. It means that depending on the type of sentence and the meaning of each sentence, you have to choose the appropriate Japanese conditional form.

It may seem difficult to select based on the conversational aspect, but once you know the requirements, it's quite simple. In fact, you have already learned the requirements to use と (to) sentence previously.

と (to) Sentence

You should remember that in the lesson on Japanese conditional form for と (to) sentence , it's mainly used in the following 4 types of sentences...

1. Nature-related Fact 2. Use of Machine 3. Give Direction 4. Somebody's Habitual Actions (Exception)

Although there are many regulations for using と (to) sentence, it's basically used in the above 4 special cases when you want to emphasize them.

ば (ba) / なら (nara) Sentence

From the conversational point of view, there are basically 2 types of sentences that require you to use ば (ba) / なら (nara) sentence...

1. When Making 2 Opposite Suppositions 2. To Show Requirement

1. When Making 2 Opposite Suppositions

Let's say your friend ask you the following question...

明日何をしますか。ashita nani wo shimasu ka

Meaning: What will you do tomorrow?

Suppose you are not sure about how is the weather tomorrow, so you give your friend 2 suppositions - "if it rains" and "if it doesn't rain". In this case, you can use ば (ba) / なら (nara) sentence.

明日雨なら、うちでテレビを見ます。ashita ame nara, uchi de terebi wo mimasu

Meaning: If it rains tomorrow, I'll watch TV at home. 雨でなければ、テニスをします。

ame denakereba, tenisu wo shimasu

Meaning: If it doesn't rain, I'll play tennis.

Since both situations are possible, you are giving 2 opposite suppositions in your answer using ば (ba) / なら (nara) sentence.

Let's look at another example. Suppose you are living in Los Angeles. You are asking your father what is the vacation plan for this coming summer.

今度の夏休み、どこへ旅行に行きますか。kondo no natsu yasumi, doko e ryokou ni ikimasu ka

Meaning: Where are we going for vacation this summer?

You father gives you 2 opposite suppositions - "if he has money" and "if he doesn't have money".

お金があれば、ヨーロッパに行きます。okane ga areba, yo-roppa ni ikimasu

Meaning: If I have money, we'll go to Europe.

お金がなければ、ディズニーランドに行きます。oakane ga nakereba, dizuni-rando ni ikimasu

Meaning: If I don't have money, we'll go to Disneyland.

Since these 2 opposite suppositions are both possible, you can use ば (ba) / なら (nara) sentence. If there's only one supposition, you should use たら (tara) sentence.

2. To Show Requirement

For this type of sentence, it normally starts with a question. For example, if you want to improve your Japanese and ask your teacher what is the requirement to do that...

先生、どうすれば日本語が上手になりますか。sensei, dou sureba nihongo ga jouzu ni narimasu ka

Meaning: Teacher, what is required (what should I do) to improve my Japanese?

どうすれば (dou sureba) in the question is asking "What is required?".

To answer this question, your teacher will most probably reply you the following sentence with the requirement...

毎日話せば日本語が上手になりますよ。mainichi hanaseba nihongo ga jouzu ni narimasu yo

Meaning: If you speak Japanese every day, it will be improved.

Therefore to show requirement, you can use ば (ba) / なら (nara) sentence.

Let's see another example. Suppose you ask your teacher about Spring...

春はどんな季節ですか。haru wa donna kisetsu desu ka

Meaning: What kind of season is Spring?

If your teacher wants to tell you the fact about Spring in Japan, she will probably answer you in the following way...

春になると、桜が咲きますよ。haru ni naru to, sakura ga sakimasu yo

Meaning: If Spring comes, the cherry blossom will bloom.

But if you change your question and ask about what is the requirement for cherry blossom to bloom with the following question...

先生、桜はいつ咲きますか。sensei, sakura wa itsu sakimasu ka

Meaning: Teacher, when will cherry blossom bloom?

OR

私は桜が見たいです。どうすれば桜が咲きますか。watashi wa sukura ga mitai desu. dou sureba sakura ga sakimasu ka

Meaning: I want to see cherry blossom. What is required for cherry blossom to bloom?

Then your teacher will most likely answer both questions with the following...

春になれば、桜が咲きますよ。haru ni nareba, sakura ga sakimasu yo

Meaning: If Spring comes, the cherry blossom will bloom.

In this case, your teacher wants to emphasize the requirement for cherry blossom to bloom, that's why she is using the ば (ba) / なら (nara) sentence.

たら (tara) Sentence

From the conversational point of view, if the sentence is not the 4 types of と (to) sentence and not the 2 types of ば (ba) / なら (nara) sentence as explained in the above sections, you can use たら (tara) sentence.

So you have to consider the 2 aspects when constructing a conditional sentence - grammatical and conversational. If grammatically the sentence is correct for all 3 conditional forms と (to), ば (ba) / なら (nara) and たら (tara) sentences, then you have to look from the conversational point of view and choose the most appropriate type of sentence to use.

One Exception for たら (tara) Sentence

While there is no regulation for たら (tara) sentence grammatically, there is one exception that you need to take note.

For all the 3 Japanese conditional forms you have learned so far, と (to), ば (ba) / なら (nara) and たら (tara) sentences, they all have one common point. It's always the case that after the condition in Sentence 1 is set, then the result in Sentence 2 happens. Time flow is always from Sentence 1 to Sentence 2.

For example, in this sentence 春になると、桜が咲きます。 (haru ni naru to sakura ga sakimasu), Spring has to come first then cherry blossom bloom. In this sentence コートを着

たら、寒くありません。 (ko-to wo kitara, samukuarimasen), it's only after you wore the coat then you are not feeling cold.

However, this is not always the case. Sometimes you may want to let the result in Sentence 2 to happen first before the condition in Sentence 1 is set. For example, if you are telling your friend "If you come to my house tomorrow, please call me before coming."

明日うちへ来ます。（来る前に）電話をしてください。ashita uchi e kimasu. (kuru mae ni) denwa wo shite kudasai

For this example, "電話をする (denwa wo suru)" happens before "coming to my house". In this case, you cannot use たら (tara) sentence. You have to use the following new form...

Verb Dict-form なら、 Sentence 2

Note: This なら (nara) is different from the なら (nara) that you have learned in ば (ba) / なら (nara) sentence. The one you have learned can only be used for な-adj or Noun sentence. This new form "Dict-form なら" is used when you want to show that the result in Sentence 2 happens before Sentence 1.

Therefore using the new form "Dict-form なら", the previous example should be...

明日うちへ来るなら、電話をしてください。 Oashita uchi e kuru nara, denwa wo shite kudasai O

Meaning: If you come to my house tomorrow, please call me before coming.

If you were to use たら (tara) sentence in the above example...

明日うちへ来たら、電話をしてください。 (grammatically correct, but meaning is wrong)ashita uchi e kitara, denwa wo shite kudasai

Meaning: If you come to my house tomorrow, please call me (at my house).

The above sentence looks weird, isn't it? You friend should call you before coming to your house. But if you use たら (tara) sentence, you are asking him to call you after he has reached your house.

Practices on Japanese Conditional Form たら and Dict-form なら Sentences

Let's check if you can tell where the speaker will like to study Japanese in the following examples using たら (tara) and Dict-form なら (Dict-form nara) sentences...

1. 日本へ行ったら、日本語を勉強しようと思います。nihon e ittara, nihongo wo benkyou shiyou to omoimasu

2. 日本へ行くなら、日本語を勉強しようと思います。nihon e iku nara, nihongo wo benkyou shiyou to omoimasu

Answers

Have you got the correct answers?

1. In Example 1 above, the speaker is going to study Japanese when he/she is in Japan because たら (tara) sentence is used. Sentence 1 in たら (tara) sentence always happen before Sentence 2.

2. In Example 2, the speaker is going to study Japanese before he/she is in Japan because Dict-form なら (Dict-form nara) sentence is used. That means the speaker is going to study Japanese in his/her own country before he/she goes to Japan.

In this lesson, we'll look at 2 special cases when constructing conditional sentences where you definitely have to use たら tara sentence.

For such sentences, you'll notice that they can also be constructed using ば (ba) / なら (nara) sentence grammatically. But for reasons that I'll discuss later, たら tara sentence has to be used invariably.

The sentence pattern for たら tara sentence is the same as the last lesson...

Sentence 1 たら、 Sentence 2

The 2 special cases when たら tara sentence has to be used are:

1. When the Condition is Different from the Reality 2. When the Condition is Definitely Going to Happen in the Future

1. When the Condition is Different from the Reality

Let's look at an example. Suppose your sister says the following...

私は男だったら、ラグビーがしたいです。 Owatashi wa otoko dattara, ragubi- ga shitai desu O

Meaning: If I were a man, I want to play rugby.

According to the rules, you cannot use と (to) sentence because you cannot have expression of personal's hope ～したい (~shitai) in Sentence 2 for と (to) sentence.

But ば (ba) / なら (nara) sentence can be used in this case because there's no regulation for Sentence 2 if Sentence 1 is a noun sentence. That means grammatically your sister can say...

私は男なら、ラグビーがしたいです。 Xwatashi wa otoko nara, ragubi- ga shitai desu X

Meaning: If I were a man, I want to play rugby.

For ば (ba) / なら (nara) sentence, there are always 2 possibilities: either "if it happens" or "if it doesn't happen", either "if it rains" or "if it doesn't rain". Both possibilities can happen. If your sister says 私は男なら、ラグビーがしたいです。 (watashi wa otoko nara, ragubi- ga shitai desu), it means she has the possibility of becoming a man. However, in reality your sister can never be a man. It's certain that this cannot happen and therefore you cannot use ば (ba) / なら (nara) sentence here. You have to use たら tara sentence.

The meaning behind the above example is that your sister is not a man, therefore she cannot play rugby 私は男ではないから、ラグビーができません。 (watashi wa otoko dewanai kara, rugubi- ga dekimasen). But if she is a man, she wants to play rugby. For this kind of assumption which is different from the reality, you have to use たら tara sentence.

Another Example

私は鳥だったら、日本へ飛んで行きたいです。 Owatashi wa tori dattara, nihon e tonde ikitai desu O

Meaning: If I were a bird, I want to fly to Japan.

If you use ば (ba) / なら (nara) sentence which is correct grammatically...

私は鳥なら、日本へ飛んで行きたいです。 Xwatashi wa tori nara, nihon e tonde ikitai desu X

Meaning: If I were a bird, I want to fly to Japan.

The above example means you have the possibility to become a bird, which is impossible in reality. Therefore you can only use たら tara sentence.

One More Example

私は百万ドルがあったら、世界旅行をします。 Owatashi wa hyakuman doru ga attara, sekai ryokou wo shimasu O

Meaning: If I have one million dollar, I'll tour around the world.

Grammatically you can use ば (ba) / なら (nara) sentence and say the following...

私は百万ドルがあれば、世界旅行をします。 Xwatashi wa hyakuman doru ga areba, sekai ryokou wo shimasu X

Meaning: If I have one million dollars, I'll tour around the world.

But in reality, it's quite impossible for you to have a million dollars. You are just dreaming. While there's a possibility that you'll have a million dollars in the future, it's impossible (at least) for the moment when you are saying the sentence. Again, the correct way here is to use たら tara sentence.

2. When the Condition is Definitely Going to Happen in the Future

If the condition is definitely going to happen in the future, it's not a conditional sentence anymore.

In the previous lesson you have learned a similar example like the following...

雨が降れば、うちにいます。ame ga fureba, uchi ni imasu

Meaning: If it rains, I'll stay at home. 雨が降らなければ、サッカーをします。

ame ga furanakereba, sakka- wo shimasu

Meaning: If it doesn't rain, I'll play soccer.

You don't know whether it's going to rain. So you use ば (ba) / なら (nara) sentence to make 2 opposite suppositions - "if it rains" and "if it doesn't rain". These are conditional sentences where both situations are possible to happen. You can also use たら tara sentence for the same example...

雨が降ったら、うちにいます。ame ga futtara, uchi ni imasu

Meaning: If it rains, I'll stay at home. 雨が降らなかったら、サッカーをします。

ame ga furanakattara, sakka- wo shimasu

Meaning: If it doesn't rain, I'll play soccer.

But if you know that the condition is definitely going to happen in the future, it's not a conditional sentence anymore. In this case, you have to use たら tara sentence. For example, if you are a student and say the following sentence...

夏休みが来たら、大阪へ行きます。natsu yasumi ga kitara, oosaka e ikimasu

Meaning: When summer vacations comes, I will go to Osaka.

All students have summer vacation, so it's definitely coming. In this case it becomes "When summer vacation comes", not "If summer vacation comes".

If you were to use ば (ba) / なら (nara) sentence for the above example, 夏休みが来れば、大阪へ行きます。 (natsu yasumi ga kureba, oosaka e ikimasu). This sounds like you are not sure whether summer vacation is coming. If it comes, you will go to Osaka. If it doesn't come, you will do something else. This sounds weird because summer vacation is definitely coming for every student.

Another Example

Let's look at another example. Suppose the time now is 9pm and you are going to bed at 11pm.

１１時になったら、寝ます。juuichi ji ni nattara, nemasu

Meaning: When it's 11pm, I will go to bed.

Time is always moving and you know that 11pm is definitely coming in 2 hours' time. So this is not a condition anymore and therefore you have to use たら tara sentence. If you say １１時になれば、寝ます。 (juuichi ji ni nareba, nemasu), you don't know if 11pm is coming, which means there is a possiblity that 11pm is not coming.

One More Example

Imagine you are 19 years old now and the minimum age in your country that you need to reach in order to get a driving license is 20 years old. You want to get your license once you reach the qualified age.

二十歳になったら、免許を取ります。hatachi ni nattara, menkyo wo torimasu

Meaning: When I reach 20 years old, I will get the driving license.

You know that we all become older every year and nobody can avoid this. In the above example, you are definitely going to reach 20 years old in the future. Therefore you have to use たら tara sentence. If you try to use ば (ba) / なら (nara) sentence and say 二十歳になれば、免許を取ります。 (hatachi ni nareba, menkyo wo torimasu), you are not sure whether you will reach 20 years old. That sounds weird and incorrect.

Conclusion

In all the above examples, although you can also use ば (ba) / なら (nara) sentence and they are all grammatically correct, the meanings are totally different. Therefore, when the condition is different from the reality and when the condition is definitely going to happen in the future, you have to use たら tara sentence.

1. 電気をつけると、明るくなります。denki wo tsukeru to, akaruku narimasu

Meaning: If you turn on the light, it will become brighter. 2. 春になると、桜が咲きます。

haru ni naru to, sakura ga sakimasu

Meaning: If Spring comes, the cherry blossom will bloom. 3. ２と３を足すと、５になります。

ni to san wo tasu to, go ni narimasu

Meaning: If you add 3 to 2, it will become 5. 4. 暑いと、喉が渇きます。

atsui to, nodo ga kawakimasu

Meaning: If the weather is hot, you will get thirsty. 5. 静かだと、よく眠れます。

shizuka da to, yoku nemuremasu

Meaning: If it's quiet, you can sleep well. 6. ２０歳以上だと、日本ではお酒が飲めます。

hatachi ijou da to, nihon dewa osake ga nomemasu

Meaning: If you are above 20 years old, you can drink alcohol in Japan.

Let's take a look at some examples which make use of Negative forms...

1. 夜電気をつけないと、暗いです。yoru denki wo tsukenai to, kurai desu

Meaning: If you don't turn on the light in the night, it's dark here. 2. 雪が降らないと、スキーができません。

yuki ga furanai to, suki- ga dekimasen

Meaning: If there is no snow, you cannot ski. 3. 何も食べないと、痩せます。

nanimo tabenai to, yasemasu

Meaning: If you don't eat anything, you will become thin. 4. 背が高くないと、モデルになれません。

se ga takakunai to, moderu ni naremasen

Meaning: If you're not tall, you cannot become a model. 5. 静かでないと、よく眠れません。

shizuka denai to, yoku nemuremasen

Meaning: If it's not quiet, you cannot sleep well. 6. いい天気でないと、遠くの山が見えません。

ii tenki denai to, tooku no yama ga miemasen

Meaning: If the weather is not good, you cannot see the mountain far away.

Rules of Using the Japanese Conditional Form と (to) Sentence

From the above examples, you will notice that...

と (to) sentence expresses Sentence 2 inevitably as a result of Sentence 1. It means whenever the condition in Sentence 1 is set, result in Sentence 2 will always happen. Therefore expressions used in Sentence 2 are natural and predictable events/states or unavoidable facts.

Based on the above 'rules', と (to) sentence is mainly used in the following 3 types of sentences...

1. Nature-related Fact 2. Use of Machine 3. Give Direction

Note: Expressions of one's will, hope, judgement, permission, order, invitation or request, etc cannot be used in Sentence 2.

1. Nature-related Fact

In one of the above examples...

春になると、桜が咲きます。haru ni naru to, sakura ga sakimasu

Meaning: If Spring comes, the cherry blossom will bloom.

...it's a nature-related fact we know that "If Spring comes, the cherry blossom will bloom". The cherry blossom will not bloom in Summer, Autumn and Winter.

Another example on nature-related fact...

祖父は眼鏡をかけないと、新聞が読めません。sofu wa megane wo kakenai to, shinbun ga yomemasen

Meaning: If my grandfather does not wear glasses, he can't read the newspaper.

2. Use of Machine

When you use the train ticketing machine, if you press the button of the 200 yen ticket after inserting the money, the 200 yen ticket will be dispensed. The 180 yen ticket or 220 yen ticket will not be dispensed if you press the 200 yen ticket's button. You can use Japanese conditional form と sentence for this kind of situation (using of machine).

このボタンを押すと、２００円の切符が出ます。kono botan wo osu to, 200 yen no kippu ga demasu

Meaning: If you press this button, 200 yen ticket will come out.

Another machine example...

このノブを回すと、音が大きくなります。kono nobu wo mawasu to, oto ga ookiku narimasu

Meaning: If you turn this knob, volume will go up.

3. Give Direction

The locations of buildings, places, etc do not change. Unless a building was demolished and relocated to another place, you will always find the same building at the same location. Therefore Japanese conditional form と sentence can be used when giving direction to places. For example...

まっすぐ行くと、右に病院があります。massugu iku to, migi ni byouin ga arimasu

Meaning: If you go straight, you will find the hospital on the right.

Another example...

あの交差点を左に曲がると、郵便局があります。ano kousaten wo hidari ni magaru to, yuubinkyoku ga arimasu

Meaning: If you turn left at that crossroad, you will find the post office.

Example of Wrong Use of と Sentence

It's stated that expressions of one's will, hope, judgement, permission, order, invitation or request, etc cannot be used in Sentence 2 of Japanese conditional form と Sentence.

If you say 春になると、日本へ行きます。 (haru ni naru to, nihon e ikimasu), it means "If Spring comes, I will go to Japan". The second sentence here is a personal will, which cannot be used in the Japanese conditional form と sentence according to the rules. Therefore this sentence is incorrect in Japanese context.

This is a common mistake. Probably the speaker wants to say "When Spring comes, I am going to Japan". It sounds perfect for English. But remember that for と sentence, whenever condition in Sentence 1 is set, the result in Sentence 2 will always happen. In this example, "going to Japan" is a one-time event. It doesn't happen for every Spring. Therefore と sentence cannot be used in this situation.

Exception

However, if the event of "going to Japan" is a habitual action, that means you go to Japan every year (without fail) when Spring comes, then you can use と sentence. You have to put 毎年 (maitoshi) which means every year to make the action habitual.

毎年春になると、日本へ行きます。maitoshi haru ni naru to, nihon e ikimasu

Meaning: Every year when Spring comes, I go to Japan.

You have already learned たら tara sentence in lesson 27 and 28. In those two lessons, with the following sentence pattern...

Sentence 1 たら、 Sentence 2

...basically you learned about:

1. Conditional Sentence

明日雨が降ったら、うちでテレビを見ます。ashita ame ga futtara, uchi de terebi wo mimasu

Meaning: If it rains tomorrow, I will watch TV at home.

2. When (where the moment is definitely happening in the future)

二十歳になったら、車の免許を取りたいです。hatachi ni nattara, kuruma no menkyo wo toritai desu

Meaning: When I become 20 years old, I want to get a driving license.

In this lesson, you will be learning yet another function of たら tara sentence - Discovery. The sentence pattern is similar, except that Sentence 2 is always in past tense.

Sentence 1 たら、 Sentence 2 (Past tense) - Express fact in the past

The conjugation for Sentence 1 is the same as before, only with the difference that Sentence 2 is in the past tense. You might recall that Sentence 2 is always in present tense in lesson 27 and 28.

This expression indicates that Sentence 2 is realized or noticed when Sentence 1 is realized. Sentence 1 is always an action and Sentence 2 must be a state. Sentence 2 cannot be an action.

Basically you'll use the above sentence pattern in two cases.

First Case to use たら tara Sentence for Discovery

Through the action in Sentence 1, Sentence 2 (what had already occurred or happened) was discovered (surprisingly).

Sentence 2 often ends with "～て-form いた" or "～て-form いました".

Let's look at one example...

カーテンを開けたら、雨が降っていました。ka-ten wo aketara, ame ga futte imashita

Meaning: When I opened the curtain, I discovered that it was raining.

In the above example, both events have already happened.In the past, I opened the curtain and discovered that it was raining

ドアを開けたら、大きい犬がいました。doa wo aketara, ookii inu ga imashita

Meaning: When I opened the door, I discovered that there was a big dog.

The dog has already been in front of the door before I opened it. But only when I opened the door, then I discovered that the big dog was there.

デパートへ行ったら、休みでした。depa-to e ittara, yasumi deshita

Meaning: When I went to the department store, I discovered that it was closed.

The department store was closed today. But I didn't know about that. Only when I went there, then I found out that it was closed.

学校に着いたら、授業が始まっていました。gakkou ni tsuitara, jugyou ga hajimatte imashita

Meaning: When I arrived at school, lesson had already started.

The lesson had started before I arrived at school. I only discovered that when I reached there.

郵便受けを開けたら、友達からの手紙が来ていました。yuubinuke wo aketara, tomodachi kara no tegami ga kite imashiata

Meaning: When I opened my letter box, I discovered that the letter from my friend had already arrived.

The letter from my friend arrived before I opened the letter box.

Second Case to use たら tara Sentence for Discovery

Sentence 2 occurred as a result of some action in Sentence 1 (unexpectedly).

アイスクリームを食べたら、お腹が痛くなりました。aisukuri-mu wo tabetara, onaka ga itakunarimashita

Meaning: I ate ice-cream, then I had a stomach-ache. (As a result of eating ice-cream, I had a stomach-ache)

Both events had already happened in the past. That means, in the past, I ate ice-cream, then I had a stomach-ache. If I didn't eat ice-cream, I wouldn't have a stomach-ache.

Similarly, for the rest of examples, something happened unexpectedly as a result of the actions in Sentence 1.

コーヒーを飲んだら、寝られませんでした。ko-hi- wo nondara, neraremasendeshita

Meaning: I drank coffee, and I couldn't sleep. (As a result of drinking coffee, I couldn't sleep)

宝くじを買ったら、８００ドル当たりました。takarakuji wo kattara, happyaku doru atarimashita

Meaning: I bought lottery, and I won $800. (As a result of buying lottery, I won $800)

ジムに行ったら、田中さんに会いました。jimu ni ittara, tanaka san ni aimashita

Meaning: I went to the Gym, and I met Ms Tanaka there. (As a result of going to the Gym, I met Ms Tanaka)

Summary

In the first case of たら tara Sentence for Discovery, it normally delivers a surprise feeling. You discovered something and become surprised. In the second case, what happened next (as a result of the first action) was unexpected.

In either case, the most difficult part is the regulation you need to take note of when using this sentence pattern.

Regulation - when using たら tara Sentence for Discovery

Intentional acts by the speaker cannot be used in Sentence 2

This regulation is quite self-explanatory because if you have speaker's intentional action in Sentence 2, it's no longer a discovery, nor it's a surprised or unexpected event.

Let's see an example...

去年日本へ行きました。ホテルに泊まりました。kyonen nihon e ikimashita. hoteru ni tomarimashita

Meaning: I went to Japan last year. I stayed in a hotel.

Both events in the above example are facts in the past. I went to Japan last year and I stayed in a hotel. However, you cannot connect the two sentences with たら tara sentence. Because the action of staying in hotel was an intentional act decided by you. You chose to stay in a hotel. This is not a surprised or unexpected event.

You cannot say...

去年日本へ行ったら、ホテルに泊まりました。 Xkyonen nihon e ittara, hoteru ni tomarimashita X

But you can say...

去年日本へ行って、ホテルに泊まりました。kyonen nihon e itte, hoteru ni tomarimashita

Meaning: I went to Japan last year and stayed in a hotel.

The above example was just two actions in order of occurrence using て-form. First I went to Japan, then I stayed in a hotel.

Therefore, for たら tara Sentence for Discovery, no intentional acts by the speaker in Sentence 2.

...taraThis "if"expression uses, with the verb "iku" as an example, the verb form of "ittara," which has an element of "itta," past or perfect meaning in it. So this one carries the meaning of: (1) "when one action *has* happened...," as well as (2) the equivalent if "if something happened..." the hypothetical IF conditional. - Kyoto ni ittara, omiyage wo katte kite kudasai. (When you're in Kyoto/when you've gotten to Kyoto, please buy me a souvenir.)- Kyoto ni ittara, oishii mono ga takusan taberaremasu yo. (If you go to Kyoto, you will be able to enjoy a lot of delicious food.) - Kyoto ni iketara, ureshii. (If I could go to Kyoto, I'd be happy.) - In this case I took "...tara" form of "ikeru," "can go."

...naraTaking the same verb for example, "iku nara":- Kyoto ni iku nara, XXX ryokan ga ii desu. (If you are to go to Kyoto, traditional inn XXX would be good/my recommendation.) "...nara" is like "if you are to...." another IF conditional, but referring more forward-looking than "...tara."

... baTaking the same verb, it would be "ikeba." This expression is used when you want to say things like "If you do A, the *natural consequence would be* B" type of "if" sentences. For example,- Kyoto ni ikeba, furui nihon ga miraremasu. (If you go to Kyoto, you'll be able to see old Japan.)- Nihon ga donna kuni ka, kureba wakarimasu. (You will understand what kind of country Japan is, if you (only) come.)

K has given a very detailed explanation. Allow me to sum up everything then. ^_^

1) A tara B (where B is in present tense): If A, B. (No restriction to B)Eg. Sensei ni kiitara, sugu wakarimasu. (If you ask the teacher, you will understand right away.)

2) A tara B (where B is in past tense): When A, B. (B is something unexpected)Eg. Uchi e kaettara, uchi ga arimasen deshita. (When I got home, my house was gone.)

3) A nara B: If A, B. (B is a piece of advice/recommendation)Eg. Nihongo no hon wo kau nara, Kinokuniya de katta hou ga ii desu yo. (If you are buying Japanese books, I would advise you to get it at Kinokuniya.)

4) A ba B: If A, B. (B must be non-volitional)Eg. Nihon e ikeba, fuji san ga miraremasu. (If you go to Japan, you'll be able to see Mount Fuji)

o: 2.An unpredictable event3. A habitual event

-ba: Unlike the sentence led by "to"clause, "ba" is used in expressions which reflect the speaker's will,judgment, permission, view, order or request.-In the sentence using ba, there is an opposite situation in speaker's mind.

Nara: It is used when the speaker addresses the topic introduced by the other person as the main theme. The sentence preceded by "nara" often expresses the speaker's advice, suggestion, requirement, or judgment.

I found this statement below too:“We are expert Japanese teachers. We are confident that this article is good and useful for foreign learners of Japanese.”

This month I will show you the usages of "to" "ba" "tara""nara"and each character.We use them to describe conditions.In some sentences we can use theminterchangeably, but in others we cannot.

1 TO(construction)Verb ,I-adjective -- Dictionary form + to (kaeru to, samui to)Na-ajective , Noun -- Dictionary form + dato (genki dato, kodomo dato)(Meaning )1. An inevitable result such as a natural and predictable event.

Haru ni naru to hana ga saki masu.(When spring comes, flowers bloom.)Okane o ireru to kippu ga demasu.(Insert money into the machine,and you'll get a ticket.)2 An unpredictable eventDepartment store ni iku to yasumi datta.(When I went to the department store , I found it closed.)

Asa mado o akeru to jimen wa yuki de masshiro datta.(In the morning I opened the window and found the ground was covered with snow.)Ie ni kaeru to tomodachi ga matte ita.(When I came back home , I found my friend was waiting for me.3 A habitual eventOkiru to sugu kao o arau.(As soon as I get up.I usually wash my face.)<< The character of "To".As I mentioned above "to"-clause leads an inevitable situation,so it is not usedin expressions which reflect the speaker's will, judgment, permission, view,order or request.So we can say,

Okane ga naito nanimo kaemasen.(If you have no money,you can't buyanything.)But we can't say,+ Okane ga nai to hataraki nasai.(If you have no money,work hard)+ Haru ni naruto yamanobori o suru tsumori desu.(When spring comes,I'mgoing to go mountain-climbing.)

2 BA(construction)Verb 1-group--eba 2-group--reba ,(sakeba, orireba)I-adjective --kereba ,(ookikereba)Na-ajective Noun -- naraba -->Look 3 NARA(shizukanaraba ,gakuseinaraba)(Meaning )1 Subjunctive* Unlike the sentence led by "to"clause, "ba" is used in expressions which reflect the speaker's will,judgment, permission, view, order or request.Yasu kereba kaimasu.(If it's cheaper, I will buy it.)

Ashita harereba dekake masyoh.(If it is fine tomorrow , let's go out.)Ame nara ba doko emo ikimasen.(If it rains,I won't go anywhere.)Okane ga nakereba hataraki nasai.(If you have no money,work hard)2 An inevitable result such as natural and predictable event.( Similar usage to "to "-1)Haru ni nareba hana ga saki masu.

(When spring comes, flowers bloom.)Kuruma ga fuereba kuhki ga yogoreru.

(If the number of cars increases ,we'll have more air pollution.)* "ba" is usually used in the present tence except the following cases.1)When it is used in a subjunctive mood, this sentence often containsspeaker's regret.Watashi ga tori nara(ba) anata no tokoro ni tonde iketa(noni).(If I were a bird, I could have flown to you.)Okanega nareba ryokou ni iketa(noni).(If I had had enough money, I could have traveled.)2) The past habitual event.Kodomo no koro tennki ga yokereba yoku soto de asonda.(When I was a child, I would play outside if the weather was fine.) <<The character of "BA"In the sentence using ba, there is an opposite situation in speaker'smind.ex) Ame ga fureba picnic ni ikimasen.(If it rains,I won't go on a picnic .But if it is fine,I'll go on a picnic.)Okane ga areba ryokoh ni ike masu.(If I have money, I will be able to travel. But if I don´t have money, I won´t be able to travel) Motto renshuh sureba nihongo ga jouzuni narimasu.(If you practice harder, your Japanese will improve)

3 TARA

(construction)Verb ,I-adjective , Na-ajective -- Past form + tara (haittara, warukattara, johbudattra)Noun -- Noun + dattara (isya dattara)(Meaning )1 SubjunctiveAshita ame ga futtara iki masen.(If it rains tomorrow , I won't go .)Yasu kattara kaimasu.(If it's cheaper, I will buy it.) Moshi komattara o denwa kudasai.(If you are in trouble , please call me.)Moshi kanojo ga dokushin dattara date shitaidesu.(If she is single, I want to date her.) # This usage is similar to Ba-1,so these sentences can be restatedwith "ba" .Ashita ame ga fureba iki masen.Yasu kereba kaimasu.2 unpredictable eventsMado o aketara umi ga mieta.(When I opened the window , I could see the sea.)Department store ni ittara yasumi datta.(When I went to the department store , I found it closed.)3 a certain resultKusuri o nondara naotta.

(After taking a medicine, I got well).# 2and3 can be restated with "to"Mado o akeru to umi ga mieta.Department store ni iku to yasumi datta.Kusuri o nomuto naotta.4 Future perfect ,( expresses certain future )Hon o yondara kashite kudasai.(After you finish reading the book, please lend it to me)

Ohsaka ni tsuitara denwa o kudasai.(When you arrive at Ohsaka, please call me.)* Usages 2,3 and 4 can not be restated with "ba". And usages 1,4can not be restated with "to"<< The character of "TARA".Unlike "ba" there is no opposite situation in the speaker's mind,Among ba, tara, nara and tara can be used the most widely.Usage no.4 of "tara" is the characteristic usage of "tara" ,so it can not be restated with "to" "ba" "nara".

4 NARA

(construction)Verb ,I-adjective , Na-ajective -- Dictionary form + nara (surunara, oishinara, hansamunara)Noun -- Noun + nara (coffee nara)

<<the character of "NARA"("Nara" has slightly different usages from “to”, “ba” and “tara”)It is used when the speaker addresses the topic introduced by the other person as the main theme. The sentence preceded by "nara" often expresses the speaker's advice,suggestion,requirement, or judgment.1 A : Nihonngo ga motto jouzu ni naritaina.(I wish Icould speakJapanese more fluently)B : Nihongo ga jouzu ni naritai nara takusan no hito to nihon-go de hanasu kotoda.(If you want to improve your Japanese , you had better speakJapanese with your friends.)2 A : Raisyu chuhgoku e ikimasu.( I'll go to China next week.)B : Chuhgoku e iku nara otya o katte kite kudasai.

(If you go to China , please buy chinese tea for me.)3 A : Ano mise ii kutsu ga yasui soudesu yo.(I heard that they sell good and cheap shoes at that shop)B : Yasuinara issyoni ikimasyou. (Then let's go together)4 A : kondo no nichiyoubi eiga o mini ikimasyou.(Let's go to the movie next Sunday.)B :Iiyo. kondo no nichiyoubi nara daijoubu.( Ok Let' s, I'm free next Sunday)..

*Na-adj. and noun + nara have two usages. One is this usage, the other is subjunctive( see above ba-1)Amenara ikimasenn.(If it rains, I won't go)Shizuka nara nerareta noni. (If it had been quiet, I could have slept well. )

Please choose an appropriate word in the following sentences.

1 Hima ga ( aruto attara ) tetsudatte kudasai.2 TV o ( tsukeruto tsukereba ) news o yatte ita.3 Coffee o ( nomunara nomeba )ano mise ga ii desu.4 Jisyo o ( hikunara hikeba ) wakari masu.5 4-gatsu ni ( nattara narunara ) ohanami ni ikimasyoh.6 ( Dekireba Dekiruto ) hayaku kaeritai.7 Syujin wa asa ( okirunana okiruto ) sugu mizu o nomu.8 Passport ga ( hitsuyohdato hitsuyohnara ) motte kimasu.

(Answer)1 attara 2 tukeruto 3 nomunara 4 hikeba 5 nattara 6 dekireba 7 okiruto 8 hitsuyohnara