What it means
なさい attaches to the masu-stem of a verb to give a direct command. It is commonly used by a parent, teacher, or other person in authority when telling someone to do something. Although it sounds softer than the plain imperative form, it is not a polite form for ordinary respectful conversation.
Usage note
なさい can sound bossy when used between equals or toward strangers. For a respectful request, use the ～てください construction instead.
Example sentences
寝る前に、明日の準備をしなさい。
Before going to bed, prepare for tomorrow.
先生の話をよく聞きなさい。
Listen carefully to the teacher's explanation.
母は子どもに野菜を全部食べなさいと言いました。
The mother told the child to eat all the vegetables.
テストの前に、教科書の