Differences among -たら, なら, -と, -んだったら, -ば, etc

Question

The Japanese language has a lot of patterns for "if" clauses. What are the differences among the following patterns and how do we choose to use one over the others?:

• 行くと
• 行ったら
• 行くなら
• 行けば
• 行くんだったら
• 行くのなら
• 行くとしたら
• 行くことになったら
• 行くならば

p/s: Please add any other additional "if" patterns

Answer 1

と, ば

The main clause must be a constant non-volitional reaction to the conditional clause unless the conditional clause shows state or if the subjects of the two clauses differ.

お金を入れてボタンを押すと、切符が出ます。
'When you put in money and press the button, a ticket will come out.'

春になると、観光客が増えます。
'When spring arrives, tourists increase.'

早く行かないと、遅刻します。
'If you don't leave soon, you'll be late.'

× お家に帰ると、連絡してください。
お家に帰ったら、連絡してください。
'Please contact me once you return home.'

× パリに行くと、凱旋門【がいせんもん】にも行ってみたい。
パリに行ったら、凱旋門にも行ってみたい。
'When I go to Paris, I'd like to see the Arc de Triomphe.'

× 帰宅すれば、必ずお風呂に入りなさい。
帰宅したら、必ずお風呂に入りなさい。
'When you get home, be absolutely sure to take a bath.'

わからないことがあったら、いつでも聞いてください。
わからないことがあれば、いつでも聞いてください。
'If there's something you don't understand, ask me anytime.'

父が許してくれれば、彼と結婚するつもりです。
'If my father lets me, I intend to marry him.'

と

The conditional clause must be non-past.

× 窓を開けたと、冷たい風が入ってきた。
窓を開けると、冷たい風が入ってきた。
'When I opened the window, a cool breeze came in.'

× デパートに行ったと、チョコレートが山積みになっていた。
デパートに行くと、チョコレートが山積みになっていた。
'When I went to the department store, I found mountains of chocolate piled up.'

～ば

1. The condition must have not happened yet.

明日もし雨が降れば、どうしますか。
明日もし雨が降ったら、どうしますか。
× 明日もし雨が降ると、どうしますか。
'If it rains tomorrow, what should we do?'

× 注射を打ってもらえば、すぐ直りました。
注射を打ってもらったら、すぐ直りました。
'When I had the injection, I got better right away.'

2. ～ば is the most common conditional when the emphasis is on what is required to bring about a desired result. Thus, use ～ば when the focus of the sentence is on the conditional clause:

どうすれば、東大に入学できますか。
What should I do to get into Tokyo University?

Consequently, when the succeeding clause describes an undesirable result, ～ば sounds unnatural:

？ 徹夜すれば、体調が悪くなります。

Instead: 徹夜すると、体調が悪くなります。
If you stay up all night, you'll damage your health. (～たら is also OK)

But when the preceding clause uses さえ to show the minimal criteria needed to achieve a result, ～ば is your only option:

お金さえ払えば、だれでも入会できる。
So long as they pay, anyone can join. (Neither ～たら nor ～と work here.)

3. Use when talking about what would happen if something (which is not actually true) were true:

あと1000円あれば、このコートを買えるのに。
If I had 1,000 yen more, I could buy this coat.

あのとき右に曲がれば、どうなっただろう。
If I had turned right back then, I wonder what would have happened.

Note that the tense of the following clause shows whether you're speculating on the past or non-past, and that past-tense verbs are allowed in this case.

～たら

1. Use when expressing a one-off (as opposed to constant or general) dependency. Like ～ば, this can be used when it is unknown whether the preceding clause will come true:

雨が降ったら、試合は中止です。
If it rains, the game will be called off. (～ば is also OK)

Unlike ～ば, ～たら can be used when it is a known fact that the preceding clause will come true:

午後になったら、散歩に行きましょう。
In the afternoon ("When it becomes the afternoon"), let's go for a walk. (～ば is not OK)

2. Use when the following clause shows intent, desire, or is a command/request:

食事ができたら、呼んでください。
When the food's ready, call me. (～ば is not OK unless the sentence is one of the exceptional cases mentioned above)

3. Use like ～と to show a sequential, cause-and-effect relationship between the two clauses:

田中さんにメールを送ったら、すぐ返事が来ました。
When I texted Ms. Tanaka, I got a reply right away. (～と is also OK, but not ～ば)

4. ～たら can also take the polite form (along with ～と), but this is usually heard only in formal settings:

ご感想がございましたら、ぜひお寄せ下さい。
If you have any feedback, please send it to us.

～なら

1. Use when you are drawing out a conclusion based on the first clause:

A: スーパーに行ってくるよ。
I'm going to the supermarket.

B: スーパーに行くのなら、しょうゆを買ってきて。
If you're going to the supermarket, bring back some soy sauce.

大学院に進むなら、この本を読みなさい。
If you're going to go to graduate school, read this book.

2. Use when you need the freedom to have the succeeding clause happen before the preceding clause. This is something ～と, ～ば, and ～たら cannot do:

旅行に行ったのなら、写真を見せてください。
If you went on vacation, please show me your photos. (A→B)

旅行に行くのなら、カメラを持っていくといいですよ。
If you're going on vacation, you should take a camera. (B→A)

飲んだら、乗るな。乗るなら、飲むな。
If you've had a drink, don't drive. (A→B) If you're going to drive, don't drink. (B→A)

Do note that the rule of drawing out a conclusion based on the first clause still applies in these examples.

3. Alternate forms:

• なら will sometimes have a の or ん in front of it; the meaning does not change.
• In speech, のなら sometimes becomes のだったら (or んだったら), again with no change in meaning.
• I believe ならば is a more formal, written version of なら, but I don't have a solid reference on this.

～としたら

This is one of many forms of ～とする. The ～とする form is used when setting up a supposition as the basis for succeeding statements:

有名人にばったり会うとしたら、どうする？
Supposing you happen to meet someone famous, what would you do?

新しい車を買ったとしても、それで幸せにはならないと思う。
Even supposing I were to buy a new car, I don't think that would make me happy.

じゃあ、犯人はこの部屋に入ったとしよう。目的はなんだったんだろうね。
So let's suppose the criminal entered this room. What do you imagine he was after?

～ことになったら

This is a combination of the ～ことになる form ("end up", "turn out to") and the ～たら conditional:

結婚することになったら、結婚式で歌っていただけませんか。
If it so happens that I get married, would you please sing for me at the wedding?

海外に行くことになったら、手紙を毎週書いて送るよ。
If I end up going overseas, I'll write you every week.

Variances among dialects

As if this wasn't complicated enough, a study done in 1989 by Shinji Sanada showed that Tokyo speakers and Osaka speakers sometimes differ greatly in their use of conditionals. A few examples:

もっと早く｛起きると／起きれば／起きたら｝よかった。
I should have woken up earlier.

• Tokyo: 4% と; 94% ば; 2% たら
• Osaka: 0% と; 20% ば; 78% たら

右に｛行くと／行けば／行ったら｝、ポストが見えます。
If you turn right, you can see a mailbox.

• Tokyo: 75% と; 16% ば; 8% たら
• Osaka: 4% と; 13% ば; 83% たら

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Source for ～と, ～ば, ～たら, ～なら, and dialectical variance study: 初級を教える人のための日本語文法ハンドブック (2000)

Source for ～としたら and ～ことになったら: personal experience

Answer 2

• 行ったら - "if you (happen to) go" (simple possibility)
• 行くなら - "if you're going (anyway)" (often in the sense of while you're at it)
• 行けば - "if you('d) go" (emphasis on the condition that must be fulfilled before something happens)
• 行くと - "when you go" ("…you'll find that…", focuses on what happens when the condition is fulfilled)
• 行くんだったら - "if you're about to go" (similar to 行くなら, but more immediate, possibly implying a catch)
• 行くとしたら - "suppose you were going" (hypothetical)
• 行くことになったら - "if it came to you going" (if the situation progressed to the point where...)

行くのなら can have a few difficult shades of meaning that I'm honestly having trouble summarizing in one phrase:

• ただ、面白いブログを書くために、人のブログを読むのなら今日から出来る
  "However, if you're going to read people's blogs in order to write an interesting blog, you can do that right away."
• 来たいのなら私達と一緒にきても良いです。
  "You may come with us if you want to."
• 万一彼が忙しいのなら、手伝いなさい。
  "If he should be busy, help him."
• 僕のいうことを信じないのなら、自分で行ってみてごらん。
  "If you don't believe me, go and see it for yourself."

Perhaps "in case" is the best English equivalent. 〜のなら is not usually used in speech, more in writing.

(Examples from the WWWJDIC)

Answer 3

行ったら is conditional form but it implies that the condition will not necessarily happen:

アメリカへ行ったら、わかるはずだ。

If you went to ... you would know that...

まずトイレに行ったら？　(or to give an advice) What about you go to the bathroom first?

Its polite form:

行けば

行くなら is conditional and implies that the condition will happen: if or since

アメリカに行くなら、ipadをもって帰って。

Since you're going to America bring me back an ipad.

行くんだったら

Is composed of: 行く　の　です + conditional form seen above.

行くのなら

Is composed of: 行く　の　です + conditional form seen above and it becomes 行くのなら, not 行くのですなら

行くとしたら　行くとすれば

Based on the above 2 conditional forms it adds another way to express a condition: ～とする

adding a layer of condition, insisting on the condition. (～とする is a simple condition that can be combined with others to emphasize the if)

明日行くとして、いいんですか？

Assume we go tomorrow, is it ok?

明日行くとしたら、いい？

If we suppose we go tomorrow, is that ok?

行くことになったら

As opposed to the other expressions above,　～ことになる　is not a condition.

It means, Verb becomes a reality

行くことになる

It happens I will go

行くことになったら...etc

If it happened I go there...etc

Answer 4

I would translate those as

• 行ったら - If you went (there), ...

• 行くなら - If you going to go (there), ...

• 行けば - If you go (there), (you will) ....

• 行くんだったら - If you are about to go (there), ...

• 行くのなら - If you (have plan/are thinking) to go (there), ...

• 行くとしたら - (Let's say) if you go (there), ...

• 行くことになったら - If you have to go (there), (what will you) ...

Answer 5

I liked the practical nature of the other answers, here's a more precise explanation I posted under a dupe thread.

Yeah, these are not so easy as there is a complex set of circumstances where you can use one over the other. I'll try to cover the most common usages and differences.

~ば is used in the case of a consistent relationship of cause and effect.

For example:

合格すれば、卒業が出来ます (goukaku sureba, sotsu gyou ga dekimasu) If I pass I can graduate.

雨が降れば、試合が中止になります (ame ga fureba, shiai ga chuushi ni narimasu) If it rains the match will be cancelled.

It can also be used for hypothetical statements, such as 明日もし雨が降れば、テレビを見ましょうか？ (moshi ame ga fureba, tereba wo mimashouka?) If it rains tomorrow, shall we watch tv?

It should generally not be followed by an expression of a wish, desire or command, and never by an action that has completed.

On the other hand, ~たら is usually used to indicate a particular condition being satisfied and it CAN be followed by an expression indicating a wish, desire or command, or followed by an action that has completed.

For example:

パチスロに着いたら電話ちょうだい (pachisuro ni tsuitara denwa choudai) Please give me a call when you get to Pacinko!

Or used with a completed action: 焼酎の瓶を飲んだら、歩けなくなった (shouchuu no bin wo nondara, arukenaku natta) I was unable to walk after drinking the bottle of shochu.

Or like ~ば it can be followed by a hypothetical statement: 明日もし雨が降ったら、テレビを見ましょうか？ (moshi ame ga futtara, tereba wo mimashouka?) If it rains tomorrow, shall we watch tv?

Just to boggle us further, there is ~と (more similar to ~ば) and ~なら which is a long conversation all by itself.

Answer 6

１：仮定（かてい）２：結果　３：習慣（しゅうかん）　４：以外（いがい）５：未来（みらい）

１＝たら、ば、なら。In this case　But　と　使えません
２＝たら、と、ば。In　this case But なら　使えません
３＝たら、と　だけ　使える。
４＝たら、と　だけ　使える。
５＝たら　だけ　使える。

とおもいます。Hope this help you out.