～たら
if / when
～たら is Japanese's everyday conditional. Take the past-tense form of a verb or adjective and add ら. It covers both “if X happens” and “when / after X happens”, the second clause describes what follows once X is done.
1. “If” condition
When the first clause may or may not happen, ～たら works like English “if”.
雨が降ったら、行きません。
“If it rains, I won't go.”
- 雨（あめ）= rain
- が = subject marker
- 降ったら（ふったら）= if (it) falls
- 行きません（いきません）= will not go
2. When / after
When the first clause is certain or already happened, ～たら means “when” or “after”.
家に帰ったら、手紙が来ていた。
“When I got home, a letter had arrived.”
- 家（いえ）= house, home
- に = to (direction)
- 帰ったら（かえったら）= when (I) returned
- 手紙（てがみ）= letter
- が = subject marker
- 来ていた（きていた）= had arrived
3. Suggestions: ～たらどうですか
～たらどうですか (“how about ...?”) is a gentle way to make a suggestion.
少し休んだらどうですか。
“How about resting a little?”
- 少し（すこし）= a little
- 休んだら（やすんだら）= if (you) rest
- どうですか = how about it?
～たら vs ～ば
～ば leans hypothetical and general, “if X, then Y as a rule” (押せば開く = “if you push it, it opens”). ～たら is the everyday, all-purpose conditional, and it is the one that also covers “when / after”.
How to form it
Past-tense form + ら, the sound changes are exactly the same as for た.
- 読む（よむ）= to read → 読んだら（よんだら）= if/when (I) read
- 書く（かく）= to write → 書いたら（かいたら）= if/when (I) write
- 食べる（たべる）= to eat → 食べたら（たべたら）= if/when (I) eat
- する = to do → したら = if/when (I) do
- 来る（くる）= to come → 来たら（きたら）= if/when (he) comes
- 高い（たかい）= expensive → 高かったら（たかかったら）= if it is expensive
- ない = not → なかったら = if not
Key idea
Read ～たら as “once X has happened, ...”. If X is uncertain, that comes out as “if”. If X is sure to happen, it comes out as “when / after”.
Other N4 grammar
Updated .