为什么

我不明白为什么你这么批评他。

我不明白爲什麼你這麼批評他。

I can't understand why you are so critical of him.

你为什么说要去公园散步？

你爲什麼說要去公園散步？

Why are you saying you want to walk in the park?

那解释了为什么门是开着的。

那解釋了爲什麼門是開着的。

That accounts for why the door was open.

"你为什么不去？""因为我不想去。"

"你爲什麼不去？""因爲我不想去。"

"Why aren't you going?" "Because I don't want to."

给你解释这为什么行不通要花很多时间。

給你解釋這爲什麼行不通要花很多時間。

It would take me too much time to explain to you why it's not going to work.