作主语
作主语的不定式如果很短,通常位于句首;若不定式(短语)较长时,常用it作形式主语,而把真正的主语(即动词不定式)放在后面,以避免头重脚轻。常见句型:It’s+名词(+for sb)+to do sth. 和It’s+形容词(+for/of sb)+to do sth.
注意 在“It’s+形容词(for/of sb)+to do sth.”句型中,若形容词表示与人有关的“赞美”或“批评”时用of,如:nice, kind, good, right, clever, bad...;否则用for。
考题预测
1.It’s very kind _______ you to help me.
A. with B. of C. for D. off
作宾语
不定式可作表示“意愿、企图”等动词的宾语,如want, aGREe, decide, begin, like, afford等;否定词not/never放在不定式前。
注意 动词不定式用作宾语时,如果后面跟有形容词作宾语补足语,在这样的复合宾语中,一般用it作形式宾语。
考题预测
2.The boy wants ________ his father a question about the moon.
A. asking B. to ask C. ask D. asked
3.I feel ______ easy to recite the text.
A. it B. this C. that D. what
4.She decided _______ a doctor.
A. not be B. doesn’t be C. not to be D. to not be
作宾语补足语
表示“命令、忠告”等的动词,如:tell, ask, want, wish, allow等后面常接不定式作宾补;感官动词feel, hear, see, watch等和使役动词make, let, have等后接不定式作宾补时须省去to。
注意 感官动词和使役动词既可用不带to的不定式(表示动作的全过程),也可用v-ing形式(表示动作正在进行)作宾补。另外,感官动词和使役动词在被动语态中,其前要加上to。如:
When I was walking in the street, I saw a plane flying over my head.
They are made to work 15 hours a day.
考题预测
5.My mother often asks me _______ early.
A. get up B. getting up C. to get up D. got up
6.We saw her _____ the building and go upstairs.
A. to enter B. enter C. entering D. entered
作状语
动词不定式放在come, go, live等动词后作目的状语;放在sorry, glad, surprised, pleased, angry等词后作原因状语;动词不定式作状语表示结果时常与副词too或enough连用。
注意 too...to与so...that..., (not)...enough to...的含义及相互转换。
考题预测
7.Jim is so weak that he can’t carry the box. (改为同义句)
Jim is ______ weak ______ ______ the box.
作定语
动词不定式在句中作定语时,常放在被修饰的名词或代词之后。
注意 由不及物动词与介词构成的不定式,介词一般不可省略。
考题预测
8.I have no pen ______.
A. to write B. to write on C. to write with D. write on
“疑问词+不定式”
疑问词+不定式=名词短语,可作主语、宾语或表语。
注意 名词短语可以由名词从句转换而来;疑问代词what、which、whom可以作宾语,疑问副词how、when、where不能做宾语。
考题预测
9.I don’t know ______.
A. how to do it B. what to do it C. how to do D. to do what
几种不带to的动词不定式句式
had better...,Why not...?, Will (Would) you please...?等句型后接不带to的不定式。
考题预测
10.It’s going to rain. You had better ______ there.
A. don’t go B. not go C. not to go D. not go to
Key:
1—6 BBACCB 7.too, to carry 8—10 CAB
