现在完成进行时的句型

Have you been to Shanghai before? 你以前去过上海吗？

No, I haven't been to Shanghai before.没，我没去过上海。

Yes, I have been to Shanghai before.是的，我去过上海了。

疑问：has he been doing this all the day ？否定：he hasn't been doing this all the day 肯定：he has been doing this all the day