～ばいい
Say what someone can or should do as a solution
You’ll be able to present a simple condition as the action that will solve a problem or achieve a result.
火がつきにくかったら、乾いた小枝を足せばいいよ。
hi ga tsukinikukattara, kawaita koeda o taseba ii yo.
What do you think this sentence means?
If the fire is hard to catch, all you have to do is add some dry twigs.
Suggest a simple solution
～ばいい suggests an easy, sufficient action to resolve a situation ("all you have to do is...", "you should...").
分からない言葉は、辞書で調べればいい。
wakaranai kotoba wa, jisho de shirabereba ii.
For words you don’t know, you can just look them up in a dictionary.
疲れているなら、早く寝ればいいよ。
tsukarete iru nara, hayaku nereba ii yo.
If you're tired, just go to bed early.
Attach いい to the ば-form
Conjugate the verb into the conditional ば-form (or たら-form: ～たらいい) and add いい. It indicates that taking this single action will suffice.
分からないことがあれば、遠慮なく何でも聞けばいいよ。
wakaranai koto ga areba, enryo naku nan demo kikeba ii yo.
If there is anything you don't understand, you can just ask anything without hesitating.
～ばいい vs ～ばよかった
～ばいい points forward: this one action will solve the problem. ～ばよかった looks back with regret: I should have done it, but I didn’t.
～ばいい, all you have to do is
先生に聞けばいい。
sensei ni kikeba ii.
You can just ask the teacher.
Advice for now or later.
～ばよかった, I should have
先生に聞けばよかった。
sensei ni kikeba yokatta.
I should have asked the teacher.
Regret about the past.
会場の場所が分からなければ、受付で聞けばいい。
kaijou no basho ga wakaranakereba, uketsuke de kikeba ii.
If you don’t know where the venue is, just ask at reception.
カレーが余ったら、冷凍しておけばいいよ。
karee ga amattara, reitou shite okeba ii yo.
If there’s curry left over, you can just freeze it.
電車に乗り遅れたら、次のに乗ればいい。十分おきに来るから。
densha ni noriokuretara, tsugi no ni noreba ii. juppun oki ni kuru kara.
If you miss the train, just take the next one. They come every ten minutes.
7 more examples in the grammar path — free for a limited time.