种子供应商告诉我明年情况会更好，但我不确定是否能相信他们。

The seed suppliers tell me things will be better next year, but I am not certain I trust them.

youdao

我不确定是否需要一部这么贵的车子。

I just don't know whether I need such an expensive car.

youdao

Ruby：我不确定是否应对此加以推测。

Ruby: I'm not sure I should speculate.

youdao

You always want to check your signs at the and because it's so easy to get the sign wrong, and I was hoping that it was right here because I wasn't sure, but it turned out to be right.

我们完成计算时，一定要记得检查符号,因为很容易弄错符号，刚才我就不太确定,是否弄错了符号，检查发现没有问题。

麻省理工公开课 - 热力学与动力学课程节选

To be honest, I'm not sure if you need to have gone to undergraduate

老实的说，我不确定你是否要有本科学历，

想成为律师的话 - SpeakingMax英语口语达人

I'm not sure if the Yale Library has this or not, but if they don't you could ask the librarian to get it.

我不太确定耶鲁的图书馆是否有这本书,但是如果他们没有,你们可以要求图书管理员购置

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选