我不确定这是不是真的，但彼得认为这是真的；这吓坏了他们。

I am not sure that this was true, but Peter thought it was true; and it scared them.

youdao

碰见他时问问他这是不是真的。

Ask him if this is true when you see him.

youdao

首先，问问你自己这是不是真的？

First and foremost, ask yourself if it's real.

youdao

We are honoring instead the integrity of what they're saying without thinking about whether or not it might be true.

我们事实上反而在,尊重他们所说内容的真实性,却从未想过这到底是不是真的。

耶鲁公开课 - 文学理论导论课程节选

I really have no idea whether it's a fact, and it's not important in My Fair Lady whether it's a fact.

我真的不知道这是不是真的，但是它在窈窕淑女里面真实与否并不重要。

耶鲁公开课 - 文学理论导论课程节选

And the other thing to point out, which I don't know if this is true or not, but does anyone know -- well that's part's true, does anyone know what the atomic mass of lithium is?

另外需要指出的一点是，关于这点我不知道是不是真的，有人知道--这部分是真的，有人知道锂的原子量吗？

麻省理工公开课 - 化学原理课程节选