unreif in English:

unripe fruit, grain etc is not fully developed or ready to be eaten

Here are some ideas for what you can do with unripe green tomatoes.

He’s very immature.

He often behaves like a child - he's so immature.

My brother is an immature boy.

My acquaintance's almost twenty but his behavior is a bit immature.

Grow up – stop being so immature.

He’s nearly 26 now but he’s still so immature.

He behaves in a very immature way.

She's rather immature for her age, don't you think?

He's so immature. He acts like a child.

1. If I'm immature, you're prenatal. / 2. Because you're immature, irresponsible, reckless, empty-headed and impulsive. / 3. And emotionally immature, totally dependent upon external validation.

1. If I'm immature, you're prenatal. / 2. Because you're immature, irresponsible, reckless, empty-headed and impulsive.