助动词
5 ^, W4 ^4 y; D; w 助动词没有独立的语义，主要作用是协助谓语动词表示时态、语态或构成疑问式、否定式等 ' a8 ?4 d) m2 F: S
助动词和情态动词的共同特点是需要和其他动词搭配使用才有意义，而且句子的否定式和疑问式都可通过这两类词体现 + B* `& y& J# P) L5 M
一、have/has (现在完成时), had (过去完成时)
& m( O) T2 l7 l3 P 这组助动词主要用来构成完成时态，形式为：have /has /had + 过去分词
y4 U) U; [6 R U6 i0 Q 如：I haven’t seen you for ages. ; Q& D/ k5 p' Q6 z# N% A- m, o5 j: z
She had mentioned this before. $ `* _' q: g, O$ u. u
二、be ' p1 @5 f, a5 a! J' A# f
be本身可作谓语动词，但在进行时中它是助动词，与现在分词搭配使用，缺一不可
( `: l6 m: ^+ \7 Q- r( {; c& a 如：She’s watching a football match. : Q/ V8 I2 q t; T4 D7 |
He’s looking for his favorite pet.
n$ G; E' W- {0 B& q- c+ z 此外，be和过去分词搭配构成被动语态
; v4 e' R; S8 R7 l- F( i5 P 如：The vicar was killed in a car accident.
& I' h$ x! L; L! ?* f( a 三、do/does (一般现在时), did (一般过去时) % m: K9 ]$ J- f3 v) Z! u/ ~
此组助动词用于构成疑问式或否定式
Q" J' a; E: D; U& A5 _: ] 如：He doesn’t feel like smoking at the moment.
/ t) j: _' |2 b: `" m Did you meet the manager this morning?
2 R' ~ B. ^- \- M 四、will, shall, would
' x/ X$ y# g0 e% z% f 此组助动词用于构成将来时 $ b+ C( C* b+ U2 g3 \" H' E+ M
如：He won’t be able to see you until an hour later. 7 x1 R j6 e5 |2 J4 `) r' B
Mary promised she would pay you a visit soon.
3 n2 }& e( x) g6 A7 @' h 例题：
3 k7 G8 o* J3 L( ` (1)
: z. { l* D8 K* i4 X6 I The colors of a rainbow ---- arranged in the same order. ' V( @ g. P7 o
(A) which are always ! y$ |1 G5 Z! Q& G
(B) and they are always , L0 G8 _- W2 o; h# z O" p! G
(C) always , R6 T* M0 s# b* r" @' u2 c% K# d
(D) are always
- t% ?. \/ U! {/ G+ [' B) X | 答案：D ! g1 d5 J: {: Z! K. i
解释：空格前是句子的主语，之后是过去分词短语，空格处需要补全句子的谓语，A使原句只有从句无主句；B并列句的前一个分句无谓语；arrange与color是被动关系，C是主动式，可排除；只有D助动词are恰好与arranged构成句子的谓语 |
发表于 2012-8-14 23:32:39
