形式主语从句是雅思写作中非常常用的一种句型。我们先来看一下它是如何构成的。(That + 一个完整的句子可做主语)。比如说：(That education is important) is clear.这就是主语从句的基本形式。但如果句子要是这样，主语过长。所以，我们习惯于用it来代替原来的主语。而把原来的主语放在句子的最后。这句话可改为：It is clear that education is important.这就叫做形式主语从句。
1 It is often the case that
2 It’s a fact that
3 It seems that
4 It’s said that
5 It’s reported that
6 It’s believed that
7 It’s universally accepted that
8 It’s announced that
9 It’s estimated that
10 It must be admitted that
11 It’s obvious that
12 It must be stressed out that
13 It is widely-accepted that
14 It cannot be denied that
15 It can be foreseen that
16 It’s as clear as crystal that
17 It goes without saying that
18 It is acknowledged that
19 It is well-known that
20 It is estimated that
