动词不定式的基本用法

1、,动词不定式的基本用法,1. 作主语,2. 作宾语,3. 作宾语补足语,4. 作定语,5. 作状语,6. 作表语,7. 作独立成分,8. 与疑问词等连用,1 不定式作主语 (subject),To see is to believe. To keep smiling is healthy for you. Its important to learn English well.,若不定式太长,往往用it作形式主语,不定式后置。单个不定式作主语时,谓语动词用单数。,Early to rise is a good habit To get there by bike often takes us

2、half an hour. When and where to hold the party hasnt been decided. When to hold the party and where to hold the party _been decided.,havent,2.作宾语,1)不定式作宾语的动词有许多，如want, decide, intend, expect, learn, manage, plan, promise, refuse, threaten, fail, wish, hope, pretend, choose等等。 I mean to go there at o

3、nce. I hope to finish the work in time. I plan to go to Beijing this summer. 2).不定式短语作宾语时，如果还带有宾语补足语，往往把不定式短语放在宾补之后，而用it作形式宾语。句型为“主语+find (feel, think, believe, consider,etc) +it+形容词/名词+to do sth”。 I think it our duty to obey the laws. I found it difficult to see him here.,3) 不定式用在介词but, except, 后时,

4、如果这些介词前有行为动词do的各种形式,那么介词后的不定式不带to,相反则带to.,(1). She could do nothing but cry. (2).There is nothing to do but wait. (3). I have no choice but to go.,4作宾语补足语 He asked me to go with him. He didnt allow me to go out alone. 【注意】在感官动词（see, hear, feel, listen to , notice, watch, observe等）和使役动词let, have， mak

5、e 后的补足语中，不定式不带to。但这类句子变成被动语态时，必须带to。 I saw him play in the park. He was seen to play in the park. The boss made those men work day and night. Those men were made to work day and night. I heard her sing today She was heard to sing today,3作表语,不定式作表语常表示解释或表将来的动作，主语常常是表示意向、打算、计划的词，如wish, idea, task, pur

6、pose, duty, job. To teach is to learn. My job is to help the patient. My ambition is to become a teacher. The old man seems to be sick. 【注意】如果在主语中（通常在主语从句或修饰主语的定语从句中）有实意动词do时，作表语的动词不定式省略to。 All I want to do now is fill my stomach.,1. something, anything, nothing, everything, no one 等不定代词或名词后常用不定式做后置

7、定语。,e.g. I have something to say. He is not a man to tell lies. We all have a chance to go to college.,(5). 定语,与被修饰词之间有动宾关系，如不定式是不及物动词，则需加介词。 Can you give some paper to _ (write)? I have no jewelry to _(wear). He is looking for a room to _ (live). He needs a friend to _ (play). There are three pairs

8、 of shoes for you to _ (choose).,write on,wear,live in,play with,choose from,动宾关系,主谓关系,同位关系,2. 当名词被the first ,the last, the only 等词以及形容词最高级修饰时 eg: She is always the first to come and the last to leave.,动词不定式作状语,不定式作状语时，可表示目的，原因，结果或条件。 如; 1：作目的状语 I went there to see her .（为了看你） She opened the window

9、to let some fresh air in.（为了让新鲜空气进来）,作结果状语,1：He is too tired to go any further.,2: He is not old enough to join the army.,他太累了以至于他再也走不动了。,他太小了所以不能参军。,作原因状语,不定式跟在表示“喜、怒、哀、乐”的形容词后，可以表示引起这些情感的原因。（happy sad surprised 等）,1: Im sorry to trouble you .,2: Im gald to see you .,下列结构常用带to的动词不定式。,be able/ready/

10、afraid to do sth,Its time to do sth,It takes sb some time to do sth .,cant wait to do sth,Its adj for/of sb to do sth,下列结构必须使用不带to的动词不定式。,had better do sth .,make/let sb do sth,why not do sth ？,would you please do sth .,would rather do sth than do sth .,一些动词不定式的谚语。,To see is to believe .,Eat to live

11、 , but not live to eat .,Its never too old to learn .,Not to advance is to go back .,眼见为实,吃是为了活着，但是活着不是为了吃。,活到老学到老 （学海无涯）,不进则退,写出下列句子中不定式（短语）所作的成分,1.It is our duty to clean the room. 2. I wish to finish the task on time. 3. We study hard to go to a good university. 4. My work is to clean the room every day. 5. The next train to arrive is from Washington. 6. He cant afford to buy the big house. 7.To m