我不太确定他今天会不会来。

Wǒ bú tài quèdìng tā jīntiān huìbuhuì lái.

I’m not very sure whether he will come today.

在回答前，请先确认你听懂了问题。

Zài huídá qián, qǐng xiān quèrèn nǐ tīngdǒng le wèntí.

Before answering, please first make sure you understood the question.

你能不能确定一下时间？

Nǐ néngbunéng quèdìng yíxià shíjiān?

Could you confirm the time?