大学英语：表语置于系动词后，构成主语+系（动词）+表语结构

（1）名词词组、形容词词组和介词词组作表语

She is a very responsible teacher.(名词词组)

It was indeed a terrible thing to happen.(形容词词组)

Your room is on the third floor,Sir.(介词词组)

（2）不定式结构作表语

The question is where to get the money and how to organize the work.

An artist’s business is to show the world as he sees it,not to make it better.

注意be + to do 不一定都是系表结构，这一结构常常用来表示命令或安排。

You are to wear uniforms at work.（命令）

The plane is to take off at 8∶30 p.m.(安排)

（3）动名词和分词词组作表语

His favourite sport is playing football.(动名词词组)

The door remained locked for a whole day.(名词)

注意：过去分词作表语时，起形容词作用，没有被动的意思。

He was too excited to be able to take part in the contest.

(4)代词作表语

This room is yours;the next one is mine.

Don’t worry.It’s nothing serious.

(5)名词从句作表语

Their idea is that we should build another school in this district.

The fact is that I can’t do much about this.