1. 当陈述句的主语为表示人的代词：anybody, anyone, everybody, everyone, somebody, someone, nobody, no one, these, those时，反意疑问句的主语用they。
例如： Everybody knows what I said, don’t they?
Nobody says a word about the incident, don’t they?
Somebody borrowed your bike yesterday, didn’t they?
Anybody can do it, can’t they?
2. 当陈述句的主语为表示无的代词：this, that, everything, anything, nothing, something等时，反意疑问句的主语用it.
例如： Everything is all right, isn’t it?
Nothing can stop us going forward, can it?
【俊狼猎英】团队为您解答。
追问nobody作主语是不是要看成否定， Nobody says a word about the incident, don’t they?
应该为 Nobody says a word about the incident, do they?
追答是的，刚才是笔误。
很抱歉。