他的行为非常不成熟。

His behavior is very immature.

她的决定显得有些不成熟。

Her decision seems a bit immature.

早恋常常被认为是不成熟的。

Puppy love is often considered immature.

你这样说话显得很不成熟。

Talking like that makes you seem immature.

这个水果还不成熟，不能吃。

This fruit is still immature and cannot be eaten.

由于计划不成熟，项目被取消了。

The project was canceled due to immature planning.

这种水果还不成熟，不能吃。

The fruit is still immature and not ready to be eaten.

他的行为对于他的年龄来说非常不成熟。

His behavior is very immature for his age.

他的笑话经常不成熟，并不是很好笑。

His jokes are often immature and not very funny.

他们的计划还很不成熟，需要更多的时间。

Their plan is still very immature and needs more time.