why not的英语语法?

问题描述:

why not的英语语法?
是不是有wht not do sth = why don't you do sth
那祈使句not to do sth 成立不成立?
既有not do sth 又有not do sth
祈使句只有用Dong't开头?
我记得以前老师有说Not to....是祈使句...

why not do sth = why don't you do sth 对
not to do sth 不对
not do sth 前加do才是祈使句
你再问下老师看是不是啊.没有not开头的祈使句.