答复

I have my doubts about what he said.= There are some doubts in my mind about what he said.
我对他说的话心存疑虑。
A: Do you believe it?
你相信吗？
B: I have my doubts about what he said.
我对他说的话心存疑虑。

It's hard to say.= It's difficult to say.= That's hard to tell.
这很难说。

That isn't exactly right.
不全是。
A: Do you mean this drug will clear up my trouble, Dr. Brown?
布朗医生，你是说这种药会消除我的病痛吗？
B：Mm, that isn't exactly right．
嗯，不全是。

It's not certain.= I'm not sure.
不能肯定。
That's for sure．
那肯定啦。
A: Do you think he is qualified for the task?
你认为他适合担当这个职务吗?
B：It's not certain.
不能肯定。

I hope you are right.
但愿你是对的。
A: I guess you will win the first place.
我猜你会得第一名。
B：I hope you are right.
但愿你是对的。

I can't say for certain wha will come.= I'm not sure who will come.
我没有把握谁会来。
A: I can't say for certain who will come.
我没有把握谁会来。
B: Ok, I'll ask George. He must know it.
好吧，我去问问乔治，他一定知道。

It might be true.
也许是真的吧。
A: It is said he won the prize.
听说他得了奖金了。
B：It might be true.
也许是真的吧。

There's no guarantee.= I can't guarantee it.
我不能保证。
guarantee n. & v. 担保，保证

Not exactly.= Not quite.
不完全是这样。

I think you might be mistaken.
我想你大概搞错了。
A: Why did you cheat me?
你为什么骗我？
B: I think you might be mistaken.
我想你大概搞错了。
mistaken a. 误解的，错误的

It depends.= That depends.
看情况吧。
A: How much can you earn per month?
你一个月能挣多少钱？
B：It depends．
看情况吧。

I can't say.
我说不好。
A: Can we arrive there in thirty minutes?
我们30分钟后能到吗？
B：I can't say.
我说不好。

I find it difficult to draw a conclusion.
我觉得很难下结沦。
A:Do you think they will win?
你认为他们会赢吗？
B: I find it difficult to draw a conclusion.
我觉得很难下结论。
draw a conclusion“得出结论”

I can't make up my mind.=I can't decide.= I'm in two minds about it.
我拿不定主意。

I've no idea about it．=I haven't a clue about it.
我不知道。
A：Why is he so unhappy?
他为什么这么不高兴？
B：I've no idea about it.
我不知道。

I'm not sure.=I can't say for sure.
我不太清楚。

I think so．
我想是的。
A：Is he a millionaire?
他是百万富翁吗？
B：I think so.
我想是的。

I'm not too sure of it.
这件事我不太有把握。
A: Do you know when he will come?
你知道他什么时候回来吗？
B：I'm not too sure of it.
这件事我不太有把握。

I hope so.= Hope so.
但愿如此。

I can't tell who is more capable.
我说不准谁更有能力。
A: I can't tell who is more capable.
我说不准谁更有能力。
B：Neither can I.
我也说不准。
capable a. 有能力的
tell在这里是“辨别，断定”的意思。

Let's leave it to chance.
听天由命吧。
A：What shall we do?
我们该怎么办？
B：Let's leave it to chance.
听天由命吧。

Maybe.= Possibly= Perhaps.= Probably.
可能吧。

Maybe yes, maybe no.
也许是，也许不是。
A: Do you think he is telling a lie?
你认为他在说谎吗？
B：Maybe yes, maybe no.
也许是，也许不是。
tell a lie“说谎”