很多同学都能想到用was to来填空,但是后面的时态却都用了attend.有人问为什么要用完成式.因为. @6 A9 _& \& `- y8 |1 }* w$ S7 q# ^
was (were) + 不定式完成式,这种结构表示“本来打算…,本来要…(而结果则没做)”。# g5 V! [" p+ W$ O+ h3 T: l! n* y
这个知识点很重要啊,大家可要牢记在心呢.好啦,今天我们要来复习的是have to和must:
# o, v3 e, s6 j7 x9 c0 y have to 和must在表示“必须”这个意思时是很接近的,但也有一定的区别。
) U3 Q5 G4 z( h _# @. l; T 1. have to 比较强调客观需要,表示因客观环境或事态促使而不得不做某事;must强调主观看法,表示主观上认为有必要做某事。例如:3 L- C z7 Q' w" o0 j. N/ |
I must learn another language.
9 z- o" O( q, R+ E- [- J- w" B& C& e (主观想法: I want to) E* D4 M j0 ~+ W3 m) J
I have to learn another language.
2 V! F. P. ^8 g; N* }& R: o (客观需要:身为一个外交官)0 C3 Y8 \3 @- \
You must be back before 10 o’clock.
/ f9 p3 |& M- v& v# U, h$ }9 a* q (叮嘱或命令)/ d5 d C& N" F# @, q- Q) T: t
You have to be back before 10 o’clock because the train is to leave at 10:05.(客观需要)
& i5 O7 |! z/ z$ _/ ^ 2. have to多表示义务或习惯动作;must则用于表示一种重要或急迫的事情。例如:
) L4 V: ~* ^$ Z4 L6 j We have to care for the young.(义务)
& Y( b' s5 `0 K0 @6 f' Y7 L She has to be at the office before eight every day. (习惯); u9 B. L7 R' C
You must go to the manager at once, or you’ll be dismissed.
" m/ T1 |) M7 p5 S$ S 务必马上去见经理,不然你会被开除的。(急迫的事情)9 d3 ]/ c9 V j* |$ t5 m
3. have to可用于不同的时态;而must一般只用于现在时(但也可以表示将来的情况,在间接引语中也可以表示过去时)。例如:7 v z, X) {& R: O0 T! i% W
I have to (must) leave now." l3 _2 t/ |- y& m
We’ll have to buy another TV set.' e0 V5 _( q1 U9 S
They had to put off the sports meet because of the bad weather.
, _5 u& `( j* {. \: P He said that the work must be finished within two weeks.
* V1 H* U* m6 t 4. must还可以表示一种推断和揣测,而have to则不能。例如:
7 ^: q; t# y+ {5 b2 P# p( a& C2 |: e This must be Jin’s pen.
* G" F0 c3 i& L) l 5. "must+动词完成式"可以用来表示对过去情况的揣测,而have to则不能。例如:
- H q* v8 B, Q4 u" A) O She must have read the book sometime in the past, or she couldn’t have answered the question so well.: b1 j+ C0 l; \/ ^+ U8 u
她一定在过去某个时候读过这本书,不然,这个问题她不会回答得这么好的。: H* k4 `0 H: h
Note:1 q6 ?$ T% b" v; ~ A% E
在现代英语中,have to 中不定式和疑问句式既可以按照助动词的变化规则构成,也可以按照行为动词的变化规则构成。例如:
0 C( W$ ?1 Q. W# n* A Have you to finish the work before supper?
# i e3 K% E; V: N Do you have to finish the work before supper?
, V" v- V8 @% ^- S: m: [ have got to 常可同have to换用,但有时表示不同的含义。比较:) M" E/ P* Y, i j
He has to report to the headquarters every two days.(例行公事,习惯动作), Y7 [0 \1 v+ f8 Q2 B. K
He has got to report to the headquarters every two days.(一道指示或命令,必得每天报告一次)
1 E3 I/ Z w$ L7 r' U 另外,作“有”解时,have got和have通常是可以换用的,have got更口语化,但有时表示不同的含义。比较:3 P% C' t/ ^ r
The man has a blind eye.那人有一只眼瞎了。
- C' U3 V, m# \5 z The man has got a blue eye.那人有一只眼被打青了。
- y" f; j* q2 u" p0 q) t must not表示禁止,是说话人强有力的劝告或命令,意为“一定要,不准”。因此,在回答由must引导的问题时,如果是否定的回答,表示“不必,没有必要”,不能用mustn’t,而要用needn’t或don’t have to.试比较:
! s# m S" c( U" i: x3 _5 a You must not drive fast.你不能开快车。(路险或有速度限制)+ x6 q3 b: v% r$ x; h$ y
You needn’t drive fast.(时间充裕) |