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”。