首先，it在句子中做形式主語和形式賓語

為避免語句過長而造成“頭重腳輕”的現象，常用it作形式主語，將真正的主語放在句子的後半部分。

例1：Who was it that break the window. (強調句，後文有具體解釋)

例2：It is reported that the President of Russia will visit China.

例3：I think it hard to answer the question in one go.

然後，是it在主語從句中的使用

①it+be+過去分詞+that從句

• 常見搭配：

• It is reported that……
• It is believe that……
• It is pointed out……
• It has been found that……
• It is generally thought that……
• It is imagined that……

②it+be+adj+that從句

• 常見搭配：

• It is clear that……
• It is likely that……
• It is fortunate that……
• It is strange / natural / essential / vital that……
• It is certain / possible that……

③it+be+名詞短語+that從句

• 常見搭配：

• It is a pity that……
• It is a fact that……
• It is a shame that……
• It is good news that……
• It is no wonder that……

④it+不及物動詞+that從句

• 常見搭配：

• It seems / happens that……
• It turns out /comes about……

⑤其他固定搭配

• It is reported that……
• It is imagined that……
• It has been found that……
• It is believed that……
• It is point out that……
• It is generally thought that……

動詞+it+賓補+to do

it在強調句中的使用

• 強調句句型的結構(注意：強調時間等狀語時，介詞不可以省略。)
• 例1：It is I that am right.
• 例2：It was him that / who we met at the school gate.
• 例3：It was in the park that Tom lost his watch.

not……until……結構的強調句型

• 例：It was not until ten o"clock that he went to bed.

• He didn"t go to bed until ten o"clock.