～ば／～たら
if / when (conditional)
～ば and ～たら are the two most common ways to say “if” in Japanese. ～ば is made by changing the end of a verb or adjective into the ば-form, and ～たら is simply the plain past (た) form plus ら.
Both map to English “if X, then ...”, and ～たら can also mean “when X happens” for things that are sure to happen. Unlike ～なら, which reacts to something the listener has just said (“if that is the case”), ～ば and ～たら state an ordinary condition.
1. ～ば: a general condition
Use ～ば for a general or hypothetical condition: if the first part is true, the second part follows.
安ければ買う。
“If it’s cheap, I’ll buy it.”
- 安ければ（やすければ）= if it is cheap
- 買う（かう）= will buy
2. ～たら: “if” and “when”
～たら works in almost any “if” sentence, which makes it the most flexible conditional in everyday speech.
雨が降ったら、家にいます。
“If it rains, I’ll stay home.”
- 雨（あめ）= rain
- が = subject marker
- 降ったら（ふったら）= if it rains
- 家（いえ）= home
- に = location marker
- います = will stay
Because the たら clause is imagined as already finished, ～たら can also mean “when” for something certain to happen.
日本に着いたら、電話してください。
“When you arrive in Japan, please call me.”
- 日本（にほん）= Japan
- に = destination marker
- 着いたら（ついたら）= when (you) arrive
- 電話してください（でんわしてください）= please call
How to form it
ば: change the verb’s final -u sound to -e and add ば; for い-adjectives, replace い with ければ.
たら: take the plain past (た) form and add ら.
- 買う（かう）= to buy → 買えば（かえば）= if (someone) buys
- 読む（よむ）= to read → 読めば（よめば）= if (someone) reads
- 安い（やすい）= cheap → 安ければ（やすければ）= if it is cheap
- 降る（ふる）= to fall (rain, snow) → 降ったら（ふったら）= if/when it falls
Key idea
Both patterns hang a condition on the front of a sentence. ～ば states a plain “if”, while ～たら pictures the condition as already completed “once X has happened, then ...”, which is why it can mean both “if” and “when”.
Other N4 grammar
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