| 形式主语 | 谓宾 | 真实主语 | 原句 |
|---|---|---|---|
| It | was his job | to repair bicycles ... | To repair bicycles was his job... |
| 形式主语可以让我们的句子看起来更明白，将表语提前强调。当真正的主语太长时，容易头重脚轻，所以使用一个 “It”做为形式主语来代替 | |||
除了名词、代词以外不定式(to do)、动名词(doing)也可以相当于名词来用，表达为一件事。所以识别为第三人称单数。
| 正常表达 | 形式主语 |
|---|---|
| To travel around the world is my dream. 环游世界是我的梦想。(头重了) | It is my dream to travel around the world. |
| To study English is very important. 想说一件事，以动作来开头就可以使用 to do... | It is very important to study English. 学习英语很重要。 |
| To think about the future is necessary. | It is necessary (for me) to think about the future. 考虑未来是必要的。 |
| To be here is my honor. | It is my honor to be here. 我很荣幸来到这里。 |
| 原型 (do) | 过去式 (did) | 过去分词 (done) |
|---|---|---|
| become | became | become |