1. Do you believe him?

你相信他的话吗？

2. Do you believe it?

你相信吗？

3. I think it's hard to believe.

我觉得这很难相信。

4. It's too good to be true.

哪有这等好事？

5. I don't buy your story.

我才不信你的鬼话呢。

6. Believe it or not.

信不信由你。

7. Really?

真的吗？

8. Are you kidding me?

你在逗我呢吧？

9. You must be joking.

你一定是在开玩笑。

10. Are you joking?

你开玩笑吧？

11. Are you serious?

你是认真的吗？

12. I doubt it.

我怀疑。

13. I am doubtful about that

我对此表示怀疑。

14. Don't expect me to believe this.

别指望我相信这事。

15. It can't be true.

不可能是真的。

16. How is that possible?

那怎么可能呢？

17. He is a doubting Thomas.

他是个疑心很重的人。

18. I never take him too seriously.

我从来不把他的话当真。

19. I feel puzzled.

我感到很茫然。

20. It's doubtful whether this will work.

我怀疑这会不会起作用。