why don't you可以等于why not.那why doesn't he可以等于吗?为什么!

why don't you可以等于why not.那why doesn't he可以等于吗?为什么! why not可以=why don't you why not是否等于why don't we?（why not后面用加together吗) why not是否等于why don't we Why don't you+...why not +. 是why don't he还是why doesn't he why don't you 等于什么 why not do sth.=why don't you do sth.还等于什么 why don’t you=why not还等于什么?两个空!麻烦大家答答. why didn't 可以改成why not why don't we =why not 还是why don't you=why not why 否定的用法 why not 是不是等于why don't?