Translation guide
Expressing the point in time when a state or condition is reached, often using なったら or なると.
The speaker wants to express that something will happen or be done at the time a certain state or condition comes to be.
This is the most common and natural way to say 'when it becomes' in Japanese. It uses the conditional form たら of the verb なる (to become). It implies that once the condition is met, the following action or state will occur.
春になったら、花が咲きます。
When it becomes spring, the flowers will bloom.
大人になったら、何になりたいですか。
When you become an adult, what do you want to be?
This pattern uses the conditional と and expresses a natural or habitual consequence when a certain state is reached. It is often used for general truths or repeated situations.
夜になると、星が見えます。
When it becomes night, you can see the stars.
彼は酒を飲むと、人が変わる。
When he drinks alcohol, he becomes a different person.
This pattern uses とき (when) with the past tense of なる, literally 'at the time when it has become'. It is slightly more formal or written than なったら.
必要になったとき、連絡してください。
When it becomes necessary, please contact me.
This is the conditional ば form of なる. It is less common in everyday speech and can sound literary or formal. It is used for hypothetical or general conditions.
天気が良くなれば、出かけましょう。
If the weather becomes good, let's go out.
Do not try to translate 'when it becomes' word-for-word as いつそれがなる. This is unnatural. Instead, attach the appropriate form of なる to the adjective or noun describing the state.
暗くなったら、帰ります。
When it becomes dark, I'll go home.
For い-adjectives, replace the final い with く before adding なる. For な-adjectives, add に. For nouns, add に.
夏になったら、海に行きたいです。
When it becomes summer, I want to go to the beach.
7時になると、ベルが鳴ります。
When it becomes 7 o'clock, the bell rings.
quiet → become quiet
春 → 春になる
spring → become spring
quiet → become quiet
春 → 春になる
spring → become spring