[译] 我认为他不会来参加这个会议。
[误] I have the idea that he will not attend the meeting.

[正] I have an idea that he will not attend the meeting.
[注] “have an idea that +从句”表示“认为某事可能会发生”，这是个固定结构，其中不定冠词不可以改成定冠词。