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.
& c0 L) Q5 o( X2 b. D% P" O$ G 1. may和might+ 动词完成式
( Y6 X) e' e `9 O% R4 c 此结构用于推测过去的行为。例如:
) U, w. I4 z% m: e5 Y/ V0 U! ^ She said that he might have missed the plane.她说他可能误了航班。 ' Y. R! Q6 C0 O3 o* s/ [) f& T# h
2. can和could+ 动词完成式
* l+ u1 z2 Y5 w; g0 O 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:
4 _# W3 ^+ G; U T+ H1 s( C In those circumstances we could have done better.
4 {8 r( l4 u( b6 K 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)
2 R/ b8 B- s4 x B. 推测过去的某种行动。
9 I# Z; \- ^* B% s& {7 F Where can /could she have gone? 她可能到哪里去了呢?
8 d8 _4 I' N1 {+ Y4 r: O0 |& r The boy can’t have finished reading the book so soon because it is difficult even to an adult.
' y4 g! X, P2 B 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。! C- O. W( `& x3 w6 @% i% {( ^# F3 o! `! g
Note:; w7 L% e8 u% ?* _: B
can’t和couldn’t+ 动词原形可以用来表示否定推断。例如:) l' J7 A: ]: f- @- s
He can’t be over fifty.他不可能超过50岁。 Q. J; s1 p2 `; Z
3.must +动词完成式
; P4 N9 o6 i4 k \ 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:+ e0 V; _( E* E8 T! T8 z1 ~8 k
She must have gone through a lot.
% D# p9 F7 p ~5 x# z 她一定吃过很多苦。- n6 Z0 p/ v9 h+ r( u! r. z6 u* `" w
Note:
3 n) l" i" _4 Q' q- J7 Q 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:
/ y$ f7 r" ~1 S" c2 {: K/ T+ \- ~ She looks happy; she must be having a good time.
L# X1 l: L+ u1 q9 @- s3 } q+ D2 v( z 4. needn’t+动词完成式和didn’t need to do
0 m8 q1 a( H' G 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:
. C+ B6 P8 U; k) I- r You needn’t have watered the flowers, for it is going to rain.* h" D# } J- L* @& I
你本来不必浇花的,因为天要下雨了。(但却浇了): g }! `4 J }9 v h
We needn’t have told him the news because he knew it already.
7 X2 ~& Q* y5 O4 V2 n 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:+ J. s; K: X Q0 k
I didn’t need to clean the windows. My sister did it.
: Q; r! u; n% k 我不必擦窗,我妹妹擦了。(我没有擦)1 r3 B7 i5 e$ F: b8 m
5. should +动词完成式5 B( ?# [5 l- S3 Y! z) c1 ]
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:
' S0 X2 _$ p, r) {% r You should have given her more help.
$ d% ? A0 [- E% n% v 你应该多给她一些帮助的。(但没有给)
1 t" T) x* R w1 i B. 表示推测,意为“可能”,但可能性较小。例如:" I u$ E2 u7 B- Y4 z& @
He should have finished the work by now.7 |' f0 u+ i1 V1 D: [, W5 R
他现在该把工作完成了。(推测)1 Y2 g& f" v3 u/ V$ a- y' o
C. should / would have thought意为“本以为,本认为”。例如:# k8 p7 \$ z* y
A: "Can you type?"* d+ b/ P8 l! L6 E# F9 j+ Q
B: "Certainly."0 }# d# x1 _3 u. {" S5 I9 `! f6 H
A: "Well, I should have thought you wouldn’t."1 d& o0 ]3 s% ` k
I should have thought she wouldn’t agree.
7 @6 G/ |0 N; \! x 我本来认为她不会同意的。- f( T2 o2 @5 C3 Q/ y6 d
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:
W, c4 m4 A8 I1 N5 B I should have thought it fairly good.
) K( m! I. V" ^: r6 ~ 我以为它是很不错的。6 O& @9 U- J3 Z6 P' H$ K
E. should have + 过去分词用于虚拟语气:
0 ?3 N. @* y6 x4 k7 b Had you written him, you should have known the details.5 B( ]+ K- @! a. s4 w$ n3 p+ f
6. ought to + 动词完成式
0 o: v9 W: [4 j4 u" K" p8 o: 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:* a9 I0 w$ J- X5 J* k+ c; F
You ought to have returned the book earlier.(还晚了) F0 j; f9 O6 J0 t& t# X" v/ Z
You ought to have refused her at the beginning, but now it is too late.
1 T4 l: [. ^2 I% ]1 V2 j Note:
1 W E H2 I& z- a2 t3 @6 w" O) ~ 这里的ought to也可以用should代替。 |