现在完成时

I have visited Paris twice.

我去过巴黎两次。

She has just finished her homework.

她刚做完作业。

Have you ever been to Japan?

你去过日本吗？

I haven't seen him since last month.

我从上个月起就没见过他。

We have lived here for ten years.

我们在这里住了十年了。

He has already read that book.

他已经读过那本书了。