什么成分可以充当表语

(1) 说明主语的身份、性质、状况等含义的成分,通常由形容词、副词、介词短语、名词、代词等充当.如：He became a doctor after he left high school.(高中毕业他当上了医生.) / The rubber wheels are over there.(橡胶轮子在那边.) / He does not feel like eating anything today because he has caught a bad cold.(他今天不想吃任何东西因为他得了重感冒.) / Who is it?(谁呀?)
(2) 表语只能放在连系动词(如：be,look,become,turn get,grow,feel,seem) 之后,对表语进行提问的句子除外.
(3) 代词做表语一般用主格,口语中常用宾.如：It’s I.(It’s me.)是我.
(4) 只能作表语的形容词有：sorry,afraid,alone,asleep,awake,ill,well,sure,interested等等.He was terribly sorry for his carelessness.(他很为他的粗心而歉疚.) / Please make no noise here; the baby is asleep.(请不要发出响动,婴儿正熟睡呢.) / I am only interested in sitting in a boat and doing nothing at all!(我只是对独坐孤舟无所事事感兴趣.) / I am not alone in thinking so.(并非只有我才这样想的.)
(5) 表语也可以由从句充当,详见“表语从句”.