〜たら
Conditional 〜たら (if / when / after)
Meaning
The most versatile conditional. "If/when A happens, B". Formed from the ta-form stem + ら. Used for one-time events, requests, intentions, and discoveries.
Formation
[ta-form stem] + ら (書いたら, 食べたら, したら)
Notes
Most conversational conditional. CAN be followed by requests/intentions (unlike と/ば). Also: 〜たらどう (advice "why don't you ~?"); 〜たらいいですか ("what should I do?").
Examples
雨（あめ）が降（ふ）ったら、試合（しあい）は中止（ちゅうし）です。
If it rains, the game is cancelled.
Breakdown
時間（じかん）があったら、手伝（てつだ）ってください。
If you have time, please help. (request after conditional)
Breakdown
家（いえ）に帰（かえ）ったら、連絡（れんらく）します。
When I get home, I'll contact you.
Breakdown
もし雨（あめ）が降（ふ）ったら、行（い）きません。
If it rains (by any chance), I won't go. (もし emphasizes hypothesis)
Breakdown
もっと勉強（べんきょう）したらどうですか。
Why don't you study more? (たらどう = advice)
Breakdown
どうしたらいいですか。
What should I do? (たらいいですか)
Breakdown
北海道（ほっかいどう）へ行（い）ったら、こんな物（もの）を見（み）ました。
When I went to Hokkaido, I saw something like this. (discovery)
Breakdown
⚠️ Often confused with
〜と、〜
Conditional と (whenever / when)
Two uses: (1) natural/habitual consequence — "whenever A happens, B happens"; (2) discover...
〜ば
Conditional 〜ば (if / whenever)
A general conditional — "if A, then B". Formed from the hypothetical form (仮定形) of the...
〜なら
Conditional 〜なら (if / given that)
A conditional based on the listener's stated or known information — "if it's the case that...
〜ても / 〜でも
Even if 〜ても
"Even if A, B" / "no matter if A". Indicates that B happens regardless of A. The result is...
〜場合は
In case 〜場合は
"In the event that ~ / in the case that ~". Used to discuss what to do in a particular (of...
〜ないことには
Unless 〜ないことには
"Unless ~", "without first ~ing" — nothing can proceed until this happens.
〜としたら / 〜とすれば
Supposing 〜としたら
"Supposing ~", "if we assume ~" — reasoning from a hypothetical.
〜てからでないと
Not until 〜てからでないと
"Not until ~", "unless ~ is done first" — a precondition that must come first.
〜さえ〜ば
If only 〜さえ〜ば
"If only ~", "as long as just ~" — one sufficient condition.