Japatan
Formação
- V(う段 → え段) + ば: かく → かけば、いそぐ → いそげば
- V(る → れば): たべる → たべれば、みる → みれば
- する → すれば、くる → くれば
- Vない形(ない → なければ): いかない → いかなければ
- いA(い → ければ): たかい → たかければ、いい → よければ
- なA / N + なら(ば)
Explicação
A ば B states the condition A that is needed for B. It is common for general truths and for what will happen. どうすればいいですか is a set phrase for asking advice. When A is an action verb, B should not be a request or invitation, but this is fine when A is a state such as ある or an adjective.
Exemplos
急げば、九時の 電車に 間に合います。
If you hurry, you'll make the nine o'clock train.
天気が よければ、ここから 山が よく 見えます。
If the weather is good, you can see the mountains well from here.
時間が あれば、ちょっと 手伝ってください。
If you have time, please help me a little.
図書館で 本を 借りたいんですが、どう すれば いいですか。
I'd like to borrow a book from the library. What should I do?
Observações
いい becomes よければ, not いければ. 〜なければ means 'if (you) don't ~'. For a one-time event meaning 'after ~ happens', 〜たら is more natural.
Gramática relacionada
Miniquiz
1もっと 練習（ ）、上手に なりますよ。
Resposta e explicação
Resposta: 3 すれば
If you practice more, you'll get better. The ば-form of する is すれば; the other forms do not exist.
2天気が（ ）、明日 海で 泳ぎましょう。
Resposta e explicação
Resposta: 2 よければ
If the weather is good, let's swim in the sea tomorrow. The ば-form of いい is よければ; いければ is a common mistake. Because 天気がいい is a state, an invitation can follow.
3野菜を もっと（ ）、体が 強く なりますよ。
Resposta e explicação
Resposta: 1 食べれば
If you eat more vegetables, your body will get stronger. For ru-verbs like 食べる, change る to れば: 食べれば.
