that能否省略？

可以,that可以省略。

一般来说,在以下几种情况下可以省略that:

1. 在定冠词the的后面

比如:

I think (that) the man is nice.

She said (that) the car is expensive.

2. 在名词短语的后面

比如:

I believe (that) her explanation is reasonable.

They doubt (that) my story is true.

3. 在形容词短语的后面

比如:

I'm glad (that) you're all right.

She's angry (that) he left without telling her.

4. 在最高级短语的后面

比如:

I'm happiest (that) you passed the exam.

She's most upset (that) you forgot her birthday.

5. 在情态动词的后面

比如:

She must (that) he went to work early.

You should (that) she knows about this.

6. 在表示疑问的句子中

比如:

Do you wonder (that) he hasn't shown up yet?

Did you think (that) I wouldn't notice?

总的来说,在the,名词短语,形容词短语,最高级短语,情态动词以及表示疑问的句子后,可以省略that,不影响句子的语法正确性。

省略that可以使句子更简练。但是在需要强调或突出时,也可以添加that,以清晰表达思想。

希望以上回答能够满足您的需求。若还有任何疑问,欢迎随时提问。