don't be(do not be)其实就是not be的一种形式,not 前面的动词可以是助动词,也可以是情态动词
助动词 We don't go to school on Sundays.
情态动词 You mustn't run in the classroom.
希望对你有所帮助!
Don't be ...是一个祈使句。如: Don't be nervus.别紧张。
not 放在be动词之后 一般构成主系表结构
如: The children are not good at diving. 这些孩子不擅长跳水。