主语宾语表语定语状语补语不定式V-ingV-ed主动语态被动语态一般式To doTo be done进行式To be doing完成式To have doneTo have been done完成进行式 To have been doing不定式有时态和语态的变化To finish such an essay in one week is beyond his ability.To live is to do something worthwhile.To listen closely and reply well is the highest perfection in the art of conversation.不定式作主语不定式作主语It is important to learn the right habits at an early age.its a great regret to have made such a mistake.Its a great honor for us to be present at the partyIts nice of you to think so much of us.不定式作主语，可以放在句首，也可以用 it 作形式主语，将真正主语不定式 放在句末不定式作宾语不定式作宾语We agreed to meet here but so far she hasnt turned up yet.He cant afford to buy a car.He pretended not to have seen me.I wanted to have dropped her a line, but forgot to do so. (不定式后用完成时表示没有实现的动作)四个希望三答应(hope, wish, expect, long, agree, promise, undertake) 五个想要巧安排(intend, plan, want, mean, desire, arrange) 设法学会做决定(manage, learn, decide, determine) 企图假装要选择(attempt, pretend, choose) 提供要求勿拒绝(offer, demand, refuse) 威胁准备不失败(threaten, prepare, fail)We thought it better to start early.They consider it important to get his permission动词不定式作宾语时放在句中动词不定式作宾语时放在句中,也可以用也可以用 it 作形式宾语作形式宾语,真正的宾语动词不定式放真正的宾语动词不定式放在句末在句末. The next step is to make sure that you know exactly what is required.The important thing in life is to have a great aim, and the determination to attain it.不定式作表语We need someone to help him with the typing.I have a lot of work to do.I havent got a chair to sit on.不定式作定语1.不定式表目的To do a good job, we must have the right ways.Ill write down his telephone number in order to call him later.不定式作状语2.不定式表结果He left, never to return. She was not old enough to understand all that.3. 不定式表原因We shall be very happy to co-operate with you in the project.All of us were shocked to hear the sad news.1.带to的不定式作宾补He commanded the soldiers to be silent.I rely on you to finish the work today.2.不带to的不定式作宾补I must have someone show me the way.He felt his hands tremble.不定式作宾补To tell you the truth, this is all Greek to me.To make the matter worse, it began to rain.不定式作插入语