【问】(A) I don't think he has come.

(B) I think he has not come.

我认为动词think是可否定转移的动词，因此，应把否定词not放在主句中(I don'tthink)。据我看，句(B)是错句。

【答】 句(B)也是正确的。但用得较少，句(B)的否定意义大大强于句(A)。因此，当需要强调从句的否定意义时，就可采用这种句式：

1. I suppose you don't ever write to him.

我想你从来也不给他写信。

2. I believe I haven't met you before. (CGEL)

我认为我从前没有见过你。

3. She imagined we wouldn't say anything. (CGEL)

她设想我们不会说什么的。

4. I think it isn't a good idea.

我认为那不是一个好主意。

5. I thought he was not happy. (GCE)

我认为他并不幸福。