步入成年英文

Already eighteen years old is an adult 。

成人：Adult

chengnian

I am eighteen years old, and I am an adult now.祝你新年快乐，学习更上一层楼！请记得采纳，谢谢！(*^__^*)

Having already been eighteen years old, so I have been an adult.

We are also gradually entering adulthood from adolescence. 我们也逐渐的从青春期步入成年期

成年

[词典]    adult; grown-up; grow up; come of age; be of age;

[例句]这孩子已经（到了）成年，应该自食其力了。

The boy has reached an adult age and ought to be earning his own living