二、不定式- Y7 E6 a) R# x) S, u
1、动词不定式形式:(to)+do具有名词、形容词、副词的特征;否定式:not+(to) do+ ]/ _& Z, L: E5 h
2、不定式的句法功能:
% B+ X8 u. o0 t# P(1)作主语:- b3 L! C1 t2 E7 K- k( x
To finish the work in ten minutes is very hard。: B* \2 h6 T1 j' s! I
To lose your heart means failure。$ A# _2 x) E7 q, d$ w
动词不定式短语作主语时,常用it作形式主语,真正的主语不定式置于句后,例如上面两句可用如下形式:* F2 m5 M7 w e; ~
It is very hard to finish the work in ten minutes。! _* k! M4 O3 r! i% i
It means failure to lose your heart。" f+ X# \# D5 @6 h1 P) P
常用句式有:
z, w& _% Q! R7 O; I5 K5 ~1、It+be+名词+to do。
: B% q. d: ]4 ^2、It takes sb.+some time+to do。
) y: R! |6 o! Q1 L. D3、It+be+形容词+of sb +to do。/ A( L l4 X$ w) _( S* _
4、It+be+形容词+for sb.+to do。+ |/ J7 I% Q" }- K- F
常用careless,,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise,等表示赞扬或批评的形容词,不定式前的sb。可作其逻辑主语。
5 ]; e+ e$ }! D8 @+ V# I8 e(2)作表语:+ q3 h4 ~4 j/ i
Her job is to clean the hall。! z' P7 r5 Z- G& K* ]
He appears to have caught a cold。6 M& c. S3 Z# F9 |- C
(3)作宾语: `% R# L. I) P8 p3 p
常与不定式做宾语连用的动词有:want, hope, wish, offer, fail, plan, learn, pretend, refuse, manage, help, agree, promise, prefer, 如果不定式(宾语)后面有宾语补足语,则用it作形式宾语,真正的宾语(不定式)后置,放在宾语补足语后面,例如:5 U* w. j: u$ p$ H' _5 z w
Marx found it important to study the situation in Russia. 动词不定式也可充当介词宾语,如: I have no choice but to stay here。: ~8 h7 b! i8 u5 |7 o$ h, l3 O
He did nothing last Sunday but repair his bike。
; \2 D1 m& p$ f- h动词不定式前有时可与疑问词连用,如: He gave us some advice on how to learn English。
9 c4 i" j5 | `7 c; p(4)作宾语补足语: 在复合宾语中,动词不定式可充当宾语补足语,如下动词常跟这种复合宾语:want, wish, ask, tell, order, beg, permit, help, advise, persuade, allow, prepare, cause, force, call on, wait for, invite。' x2 R' U5 X) w: g, K
此外,介词有时也与这种复合宾语连用,如: With a lot of work to do, he didn't go to the cinema。
* l! @6 h1 {: c2 f9 ^有些动词如make, let, see, watch, hear, feel, have等与不带有to的不定式连用,但改为被动语态时,不定式要加to, 如: I saw him cross the road. /He was seen to cross the road。 |