反义疑问句的一个问题

陈述部分主语是不定代词everybody, anyone, somebody, nobody, no one等，疑问部分常用复数they，有时也用单数he。
did he/ did they

did they
当主语是nobody,everybody,someone 等合成词时，反义疑问句中的主语要用they,是nothing,everything等时，要用it
nobody是没有人，否定的，所以疑问部分要用肯定的。

nobody knew him,did they?
因为nobody属于否定，那么后面就应该用肯定，然后knew是过去式，故用did

did they

did he? 或者did they? 都可以的

do anyone?