Why don't you know, papa?

你为什么不知道啊，爸爸？

You know what, why don't you go ahead and take my new car?

你知道吗，你何不开我的新车去？

My name is Lesley. My Chinese is Xu Yun. Why don't you know it?

你真笨啊我在这里当然不会用中文名了。我的英文名你不知道啊，女人?。

Melon brother: Why don't you know? Stop searching. Fear can keep us alive, don't stop being scared.

瓜哥：你为什么不知道？停止寻找吧，恐惧能让我们活着，别不害怕。

A: yes, i think i can help you. why don't you come round and see me? do you know where my office is?

是的，我想我能帮你。你为什么不过来找我呢?您知道我的办公室在哪里吗?