why don't we =why not 还是why don't you=why not

why don't we =why not 还是why don't you=why not Why don't you+...why not +. why not可以=why don't you why don't you do=why not doing why not 同义词是 why don't you 还是 why don't you do why don't和why not why not是否等于why don't we why don‘t you和why not的不同用法 why not是否等于why don't we?（why not后面用加together吗) Why not do sth.=Why don't you do sth.=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.