主 宾 表 定 状 补 不定式 √ 动名词 分 词
动词不定式 时态 一般式 to do 完成式 to have done 进行式 to be doing 完成进行式 to have been doing
不定式的用法 作主语 To live is to work. To save time is to lengthen life. 动词不定式作主语时，可以用形式主语 it 代替。而把不定式放在后面。 It is best to do so.
2. 作表语 His job is to teach English. The main thing is to keep our machine from rust. 3. 作宾语 I learn to speak Chinese. They decided to begin the experiment at once.
4. 作宾语补足语 I like you to do it this way. Please ask John to turn over the light. They advised us to wait. We are advised to wait.
5. 作定语 动词不定时作定语时，需放在被修饰的名词或代词的后面。 He said he had an important meeting to attend. 如果不定式是不及物动词，后面就应有必要的介词。 Give me a piece of paper to write on.
有很多名词常可用不定式作定语。 decision, wish, chance, promise, plan, time, attempt, effort, right, ability, patience等。 Before liberation he had no chance to go to school. I must keep the promise to pay within a month.
6. 做状语 做目的状语 He sat down to have a rest. They went there to visit their teacher. 做结果状语 He woke up to find everybody gone. My grandmother lived to see the liberation of China.
某些形容词作表语，表示喜、怒、哀、乐， 后跟不定式表示原因。 I am very glad to see you. I am so sorry to hear your mother is ill.
时态与用法 时 态 构 成 一般式 完成式 进行式 完成进行式 to do to have done to be doing to have been doing