有人问到这样一句话：

(1)Nobody thought they would have to pay for their own ticket.

这里的ticket为什么用单形而不用复形？

有些指人的复合代词，如everybody, everyone, somebody, someone, anybody, anyone, nobody, no one等，常常代之以人称代词they(them)和物主代词their，而不用he (him)和his。因此这个句子实际上等同于：

(2)Nobody thought he would have to pay for his own ticket.