Quick Answer
Three conditionals, one translation — but each frames the situation differently. ば expresses a general or logical condition ("if A, then naturally B"). たら is the most flexible — it covers completed conditions, sequences, and real-time discoveries. なら responds to a topic already in the air, meaning "if that's the case" or "given what you just said."
Comparison Table
| Form | How to Form | Core Meaning | Main Use | Result Tense |
|---|---|---|---|---|
| ば | verb (conditional stem) + ば
い-adj → ければ な-adj/noun → であれば | Logical / general condition | Advice, proverbs, hypotheticals | Non-past only |
| たら | past form (た) + ら | Sequential / completed condition | Everyday speech, discovery, sequence of events | Past or non-past |
| なら | noun / plain form + なら | Contextual / topic-based condition | Responding to what someone said, giving advice based on new info | Non-past only (result usually precedes condition in meaning) |
Detailed Explanation
ば — The Logical Conditional
Use ば when the result follows naturally or inevitably from the condition. You'll find it most in proverbs, scientific facts, and advice framing an objective relationship.
- Works best when the subject of both clauses is the same person or thing.
- Cannot be used when the result clause contains a request (〜てください), command (〜なさい), intention (〜つもり), or past discovery.
- Stative verbs (いる, ある, わかる, できる) pair very naturally with ば.
たら — The Sequential Conditional
Use たら when one event completes and another follows — whether expected or surprising. It's the safest pick of the three: when in doubt, たら rarely sounds wrong.
- Can express past discovery: 「家に帰ったら、財布がなかった。」("When I got home, my wallet was gone.")
- Can be followed by requests, commands, and volitional forms.
- Used for one-time, specific events rather than general truths.
なら — The Contextual Conditional
Use なら when reacting to what the other person said or implied. It anchors the condition in prior context. Because of this, the advice can feel like it "comes first" — you're responding to a situation already in the room.
- Common pattern: A says something → B responds with 〜なら〜
- Often used to give recommendations or warnings: 「東京に行くなら、スカイツリーがおすすめです。」
- Cannot be used for pure hypotheticals with no contextual basis.
Example Pairs
Same situation, three lenses — watch how the nuance shifts with each form.
Pair 1 — Studying and passing
勉強すれば、合格できる。
Benkyō sureba, gōkaku dekiru.
[ば] If you study (as a general truth), you can pass.
勉強したら、合格できるよ。
Benkyō shitara, gōkaku dekiru yo.
[たら] Once you've studied, you'll be able to pass (specific encouragement).
合格したいなら、勉強しなさい。
Gōkaku shitai nara, benkyō shinasai.
[なら] If you want to pass (as you say), then study!
Pair 2 — Going to Tokyo
東京に行けば、スカイツリーが見られる。
Tōkyō ni ikeba, Sukaitsurii ga mirareru.
[ば] If you go to Tokyo, you can see the Sky Tree (general fact).
東京に行ったら、スカイツリーを見てください。
Tōkyō ni ittara, Sukaitsurii wo mite kudasai.
[たら] When you go to Tokyo, please see the Sky Tree (request after event).
東京に行くなら、スカイツリーがおすすめです。
Tōkyō ni iku nara, Sukaitsurii ga osusume desu.
[なら] If you're going to Tokyo (as you mentioned), I recommend the Sky Tree.
Pair 3 — Arriving at the station
駅に着いたら、電話してください。
Eki ni tsuitara, denwa shite kudasai.
[たら] When you arrive at the station, please call me. ✓ Natural
❌ 駅に着けば、電話してください。
❌ Eki ni tsukeba, denwa shite kudasai.
[ば + request] Unnatural — ば cannot precede a request form.
Pair 4 — It being cheap
安ければ、買います。
Yasukereba, kaimasu.
[ば] If it's cheap (logically), I'll buy it.
安かったら、買います。
Yasukattara, kaimasu.
[たら] If/when it turns out to be cheap, I'll buy it (more situational).
安いなら、買えばいいじゃないですか。
Yasui nara, kaeba ii ja nai desu ka.
[なら] If it's cheap (as you say), why not just buy it?
Common Patterns
Some patterns lock in one conditional. Recognize these and you'll sidestep most common errors.
| Pattern | Form Used | Example |
|---|---|---|
| Proverbs / general truths | ば | 郷に入れば郷に従え (When in Rome…) |
| Past discovery / surprise | たら | 開けたら、プレゼントがあった。(When I opened it, there was a present.) |
| 〜ばよかった (should have done) | ば | 早く起きればよかった。(I should have woken up earlier.) |
| 〜たらどう (how about…?) | たら | 医者に行ったらどうですか。(Why don't you go to the doctor?) |
| Advice based on stated info | なら | 頭が痛いなら、休んだほうがいい。(If your head hurts, you should rest.) |
| 〜ばいいのに (I wish…) | ば | もっと早ければいいのに。(I wish it were faster.) |
| Result followed by request/command | たら | 着いたら連絡して。(Contact me when you arrive.) |
Common Mistakes
Mistake 1 — Using ば before a request or command
❌ 家に帰れば、電話してください。
❌ Ie ni kaereba, denwa shite kudasai.
Incorrect — ば cannot be followed by a request (〜てください).
✅ 家に帰ったら、電話してください。
✅ Ie ni kaettara, denwa shite kudasai.
Correct — use たら when a request or command follows.
Mistake 2 — Using なら without contextual basis
❌ もし雨が降るなら、試合は中止になる。
❌ Moshi ame ga furu nara, shiai wa chūshi ni naru.
Unnatural — なら requires a contextual premise; you cannot use it for a pure hypothetical about the future.
✅ もし雨が降ったら、試合は中止になる。
✅ Moshi ame ga futtara, shiai wa chūshi ni naru.
Correct — use たら for hypothetical future events.
Mistake 3 — Confusing なら word order (result before condition)
Learners sometimes rearrange なら sentences trying to match English word order. Don't. The key is: なら reacts to what was just said.
A: 日本語を勉強したいんです。
B: ✅ 日本語を勉強するなら、アニメを見るといいですよ。
A: Nihongo wo benkyō shitain desu.
B: Nihongo wo benkyō suru nara, anime wo miru to ii desu yo.
A: I want to study Japanese. B: If you're going to study Japanese, watching anime is a good idea.
Mistake 4 — Using たら for general/timeless truths
❌ 水を熱したら、100度で沸騰する。
❌ Mizu wo nesshitara, hyakudo de futtō suru.
Awkward — たら implies a specific event; use ば for scientific/general truths.
✅ 水を熱すれば、100度で沸騰する。
✅ Mizu wo nessureba, hyakudo de futtō suru.
Correct — ば suits general scientific facts.
Related Articles
- ために vs ように — Purpose (Comparison X vs Y)
- は vs が — Topic vs Subject (Comparison X vs Y)
- に vs で — Location Particles (Comparison X vs Y)
- ている vs てある — State (Comparison X vs Y)
- から vs ので — Because (Comparison X vs Y)
- けど vs のに — But/Although (Comparison X vs Y)
Quick Quiz
Fill in the blank with ば (conditional stem), たら, or なら.
- 疲れている ___、早く寝たほうがいい。
Hint: Reacting to something the speaker just told you.
Answer
なら — 疲れているなら、早く寝たほうがいい。
(If you're tired [as you say], you should sleep early.)
Hint: A general, timeless natural fact.
Answer
ば → なれば — 春になれば、花が咲く。
(When spring comes [as a general truth], flowers bloom.)
Hint: A request that follows a completed action.
Answer
たら → 着いたら — 駅に着いたら、メッセージを送ってください。
(When you arrive at the station, please send me a message.)