现在我们要来学习情态动词+完成时的用法,当然包括了大家最关心的虚拟语气. 3 O7 Z9 N/ U# A6 \& O9 i
1. may和might+ 动词完成式: p2 Y8 C4 `! n' C7 @
此结构用于推测过去的行为。例如:
' ~' o0 Y3 O% R; l She said that he might have missed the plane.她说他可能误了航班。
4 U/ y" f, Q8 n 2. can和could+ 动词完成式
6 h+ f$ u/ N+ F( K0 k A. 表示过去能做而没做的事,有一种对过去未付诸实施的事情的惋惜。例如:
! m3 W4 d$ M& i; x In those circumstances we could have done better.6 E' T& Q. \! z3 K/ D6 b% G& g- ]
在那样的情况下,我们本来可以做得更好的。(但没有做得更好)
5 j+ q& k6 a8 _- ? B. 推测过去的某种行动。# B0 h# B: ?3 G+ w/ g
Where can /could she have gone? 她可能到哪里去了呢?* N3 V# \. z" j6 J. i
The boy can’t have finished reading the book so soon because it is difficult even to an adult.
) ]0 A1 ?0 Y( Y( w' R 这孩子不可能那么快就把这本书读完的,因为即使对一个成人来说,这本书也是相当难的。. k1 i4 Q, F9 @& F5 z" P4 f
Note:) T6 Y- |7 G. v2 c, n* q+ i+ C
can’t和couldn’t+ 动词原形可以用来表示否定推断。例如:, }7 w* m$ K' ]+ L) t: F3 ]
He can’t be over fifty.他不可能超过50岁。
( b$ Q, y; @ _- b) a# x) m 3.must +动词完成式
! M2 G; \9 j! A4 s 表示对过去行为的推断,具有较大的可能性,意为“一定…,想必…”。例如:9 m5 j: }: R% f& X3 E
She must have gone through a lot.0 ]5 n. i% x+ ?) G% n
她一定吃过很多苦。, n. {8 m7 h* C& M& U, `, M
Note:
5 V, P& m' S7 [7 U must+动词原形→对现在的推测,must be+现在分词→对未来或现在正在进行的推测。例如:
% Z9 n W, V/ k) u' K She looks happy; she must be having a good time. . b. j7 N& E0 a
4. needn’t+动词完成式和didn’t need to do, w9 R6 M4 t) e q: Z. f
A. needn’t+动词完成式表示一种已经做过的但并无必要的行为。例如:
2 a- [4 y0 g4 f2 w You needn’t have watered the flowers, for it is going to rain.5 o# e' K% I+ ^, g+ ?
你本来不必浇花的,因为天要下雨了。(但却浇了)' d- G1 a0 z: @
We needn’t have told him the news because he knew it already.
g ~8 X; [' o B. didn’t need (have) to do结构表示没有必要做某事,实际上也没有做。例如:
" [: o, T, r, M# z/ d! S I didn’t need to clean the windows. My sister did it.3 M( r0 \ ^% o0 J( l- _
我不必擦窗,我妹妹擦了。(我没有擦)
9 ]/ o5 T2 u& E) ^! Q$ E 5. should +动词完成式
9 {3 e. [: K3 g8 Y) M7 x A.此结构的肯定式表示应该做的事而没有做,否定式表示某种行为不该发生但却发生了。例如:
. Q. Q! v! o& e v5 v$ [, Y+ w# W You should have given her more help.# y1 W) b. ]9 o/ `' Z
你应该多给她一些帮助的。(但没有给)
- \! A% t- k6 f1 @# ^ B. 表示推测,意为“可能”,但可能性较小。例如:( X5 o* d+ F% f
He should have finished the work by now.
0 `! z) `3 j+ f7 ~# G* W9 |* p- J 他现在该把工作完成了。(推测)& F& x+ w t6 I) @
C. should / would have thought意为“本以为,本认为”。例如:
* p' {( l, j; y, B A: "Can you type?"
( I6 u& `" c' o7 D B: "Certainly." }5 ~2 @" Y a+ I8 W! q2 L! S
A: "Well, I should have thought you wouldn’t.". O: W' a0 e& u5 e9 ]5 k
I should have thought she wouldn’t agree.
' h2 k' n; a3 N 我本来认为她不会同意的。
! Y6 M, c' A) T: _ D. should have thought有时意为“认为,以为”,相当于should think,但表示更为委婉、谦逊或不肯定的语气。例如:
! K/ x- l2 ^& ?$ z2 h% \9 ^; L6 T I should have thought it fairly good.& v, K6 @1 ?$ Q
我以为它是很不错的。
) V! b, S. q3 O0 a! J E. should have + 过去分词用于虚拟语气:
$ g8 e, G$ ?/ V+ T1 z, C Had you written him, you should have known the details.
' H5 F1 w# H8 ^ 6. ought to + 动词完成式" R; x. r7 i4 X6 ?5 _. } ?3 C- f$ y
此结构表示某种过去应该做而没有做的事,或被忽略未做的某种明智行为。例如:
( T$ J& h/ q! k5 K' u& t) L1 h You ought to have returned the book earlier.(还晚了)
- e7 \, C. w: ]) t You ought to have refused her at the beginning, but now it is too late. ~' ^$ C' \' a" C" ~
Note:- [! J |6 c( O, z$ J
这里的ought to也可以用should代替。 |