单数they 单数they是they或它的词形变化形式例如them或their的用法用于指单独一个人作为单数形式 典型地这种情况出现于不确定的性别例句 Everyone returned to their seats Somebody left their umbrella in the office Would they please collect it If a person doesnt want to go on living they are often very difficult to help The patient should be told at the outset how much they will be required to pay But a journalist should not be forced to reveal their sources 类似地这种情况也可以应用于派生词例如themself或themselves 这种用法的一个原因是英语没有专用于不确定性别的单数人称代词 有些情况这种用法可以被解释为一种名义约定因为如everyone之类的单词虽然在语法上是单数形式但事实上却是复数的意义 这种用法逐渐变多的一个原因可能是世纪的性别包容语言运动但是它已经被有影响力的作家使用了好几个世纪 虽然单数they的用法历史悠久并且在日常英语中广泛使用但是这种用法从世纪末开始还是一直受到批评并且大家的认可度也不同