表语：表示主语的身份、性质、状态和特征，一般由名词、形容词、或相当于名词、形容词的词、短语或句子充当，位于连系动词之后，与连系动词一起构成句子的谓语。如：
Be careful! 小心!
He looks very angry. 他看上去很生气。
His job is looking after sheep. 他的任务是看羊。
扩展资料
表语从句概述：
用作表语的从句叫作表语从句，它位于主句中的连系动词之后。引导表语从句的词有从属连词that、whether、as though(if)；关系代词who, what, which, whom, whose, whatever, whoever, whomever, whichever等；
关系副词when, where, why, how, however, whenever, wherever等。可以接表语从句的连系动词由be, look, remain, seem等。That引导表语从句时，在口语中，间或可以省略。
The trouble is that we are short of money.困难是我们资金短缺。
That is why stone walls are used instead of fences around New England fields.这就是为什么在新英格兰用石头墙而不用栅栏的原因。
参考资料来源：百度百科-表语
土豆豆的焦糖
