表语是用来说明主语的身份、性质、品性、特征和状态的，表语常由名词、形容词、副词、介词短语、不定式、动词的-ing、从句来充当，它常位于连系动词（be, become, appear, seem等）之后。
动词ing作表语的例句Her job is selling computers.她的工作是销售电脑。
My hobby is playing basketball.我的爱好是打篮球。
My job is teaching him English.我的工作是教授英语。
His job is sweeping the streets.他的工作是打扫街道。
