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. Y9 w0 T, H J& r. B. y7 i
1. may和might+ 动词完成式) O' R' G$ L+ U( f* x7 w
此结构用于推测过去的行为。例如:
9 F: e" D+ T, M& [% X" p She said that he might have missed the plane.她说他可能误了航班。 ' ?$ {3 ?5 `# x. }& H
2. can和could+ 动词完成式
1 |$ y7 R: k3 g' @3 }) a4 n5 a. n1 m 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:" q- T: X( p% f: W& M
In those circumstances we could have done better.7 u5 V. ^& R8 [4 ]* n
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); F5 s& v7 `6 \" a% l7 b% ~
B. 推测过去的某种行动。. k. b2 E8 ~! X; q& m2 U8 N
Where can /could she have gone? 她可能到哪里去了呢?
% ?1 @2 W: ?' G2 D- @ The boy can’t have finished reading the book so soon because it is difficult even to an adult.
( \0 |6 e! u9 A; {% 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。
& {& C; L4 n0 Y# ~: G5 [) Z Note:
: v7 U& _9 I$ r0 g! z can’t和couldn’t+ 动词原形可以用来表示否定推断。例如:: c n% u# n- V# h
He can’t be over fifty.他不可能超过50岁。
7 W- y9 y0 V( ^% M4 n) M 3.must +动词完成式
- v; O* @5 Z0 E f 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:
& H* O3 m+ ?0 G She must have gone through a lot.% w2 z) Q$ E1 q9 S
她一定吃过很多苦。* C9 t& [' N! E, y# n
Note:
; M$ M3 w4 P1 }% K 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:
% n' Z* Y: }+ q( L. z She looks happy; she must be having a good time. ) F \5 Y: @1 m( H* v) [7 J
4. needn’t+动词完成式和didn’t need to do/ H$ d" e: W. y
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:3 p6 T b* A: r
You needn’t have watered the flowers, for it is going to rain.- W+ r! b" _3 B1 O+ Z
你本来不必浇花的,因为天要下雨了。(但却浇了)$ t/ x! `% {) M
We needn’t have told him the news because he knew it already.( h0 ]: g( z, L1 Q1 Q& X$ A* y
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:
0 [9 B, F- L- ~7 f I didn’t need to clean the windows. My sister did it.$ h. ~+ @% x5 s- _( w$ r4 V
我不必擦窗,我妹妹擦了。(我没有擦) G* U0 }- Y6 [3 o1 U
5. should +动词完成式
7 v) k) t7 W" x$ _; u2 N4 q 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:3 T, b6 C: b! z5 S1 ]& R
You should have given her more help.* X% z5 k( o/ s- Q+ x8 Q
你应该多给她一些帮助的。(但没有给)( o5 n5 w! ]1 W: H) j8 {
B. 表示推测,意为“可能”,但可能性较小。例如:
# l/ A! C7 J# y; b: C" X He should have finished the work by now.' S+ g9 v. n: I! r6 j+ w
他现在该把工作完成了。(推测)
! ?$ X7 {: ~) l- W$ }% e/ N C. should / would have thought意为“本以为,本认为”。例如:: F+ W G% g* p' W H9 y( V m
A: "Can you type?"6 I: a: y6 r. \0 O) L
B: "Certainly."( w. V! @: ^0 ?9 |+ S7 B6 v
A: "Well, I should have thought you wouldn’t."
' L" @6 c/ g% W m3 {5 x I should have thought she wouldn’t agree.
# \( X3 m1 M: O: E- i 我本来认为她不会同意的。
" k. @ G% [1 I g( O% [ 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:
# g1 @* K- U5 B6 C) m I should have thought it fairly good./ S" [/ y$ [0 I6 P
我以为它是很不错的。' l3 B7 i5 n- x+ @% B
E. should have + 过去分词用于虚拟语气:8 g: G0 v6 T5 [" M; J
Had you written him, you should have known the details.
' i2 d$ `8 j) Y$ D7 } 6. ought to + 动词完成式
* Q8 r3 n7 s2 B) s7 z& {4 k 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:8 v1 u5 L3 G+ }. I6 M
You ought to have returned the book earlier.(还晚了)
2 i' L$ v% G1 j+ ? You ought to have refused her at the beginning, but now it is too late.
6 @3 z0 m) {: X2 q0 Q1 s Note:1 O* Q. }0 r6 b0 Q+ W. _& n2 ?
这里的ought to也可以用should代替。 |