【问】I don't think she knows French，does she?这里的反意疑问句为什么是does she，而不是do I?

【答】 可否定转移的动词的否定常常转移到宾语从句中去：

I don't think she knows French.≈I think she doesn't know French.

而反义疑问句是针对被转移否定的从句而说的，所以当然要does she?而不能do I?类例：

1. I didn't think he was happy，was he?

我认为他并不幸福，是不是?

2. I don't suppose that he cares，does he?

我认为他并不关心，是不是?