is和does的区别是什么?如：when does your brother do his homework?可不可以说成 when is your brother
如：when does your brother do his homework?可不可以说成 when is your brother do his homework?如果可以,为什么?什么情况下不可以?如果不可以,为什么?什么情况下可以?我最多可以提高悬赏10分,只要讲明白即可