作表语的从句有三类：
1 .由that 引起的表语从句：
The trouble is that we are short of funds .
困难是我们缺乏资金。
One explanation is that he wanted to be different from others .
一个解释是他想与众不同。
Your greatest fault is that you are so careless .
你的最大缺点是你太粗心。
在口语中that 有时可省略：
The fact was , she didn t want to come to the workshop at all .
事实是她根本不想到车间来。
The reason was ( that ) he was afraid .
原因是他害怕。
2 .由关系代词型what 引起的表语从句：
That's what we should do .
这是我们的本分。
Asia is no longer what it used to be .
亚洲现在己不是过去的样子了。
It's two dollars . That's what it usually is .
价钱是两美金，这是通常的价钱。
That's what I heard .
这是我听到的情况。
3 .由连接副(代)词引起的表语从句：
That's not where it belongs .
这不是它应放的地方。
Thats how they escaped.
他们就是这样逃出的。
The question is what we should do next .
问题是下一步该怎么办。
That's why I want you to work there .
这就是我要你在那里工作的原因。
That was when I was thirteen .
这是我十三岁时发生的事。
So that's whom he working for .
所以说他就是为这种人工作的。
有时表语从句可由whether 引起：
His first question was whether Holmes had arrived yet .
他第一个问题是福尔摩斯到了没有。
