why后面加什么句子

　　Why do you make things so difficult for yourself?

　　你为什么这样跟自己过不去？

　　Why can't you ever see my point of view?

　　你怎么老不明白我的观点呢？

　　I know you did it ─ I just want to know why.

　　我知道这是你干的，我只是想知道为什么。

　　Why don't we go and see it together?

　　咱们为什么不一起去看看呢？

　　It's not for me to say why he left.

　　不适宜由我说出他离开的原因。