903 Have和be可以称作特殊助动词，原因有下面几个方面。
(a)它们可用来构成许多时态及被动语态。
I have done it．I have been doing it．I had done it．
I am doing it．I shall be doing it．It was done．
(b)它们必须和主语在人称和数上一致，而其他助动词都可用于任何人称。
I can do it．You can do it．He can do it．
I may do it．You may do it．He may do it．
I will do it．You will do it．He will do it．
但：
I have done it．You have done it．He has（!）done it．
I am（!）doing it．You are（!）doing it．He is（!）doing it．
I do not know it．You do not know it．He does（!）not know it．
(c)它们也可以用作主要动词，而其他助动词多数都不能单独构成谓语。
Has he a car?I have not anything to do．
Is it true?They are not my sisters．
在作主要动词时，它们仍具有助动词的某些特点，如可放在主语前构成疑问句，可放在not前构成否定句。（参阅905，906节）
(d)它们可以用于动名词、分词及不定式中，而其他助动词都不能这样用。
Having done it，he went home．
His having studied psychology is the reason for his success．
I wished to have learned German．
Being asked about it，he replied．
I told him about his being promoted．
He seems to be studying it．
b．必须使用助动词的情况
904 在下面12类句子中都必须使用助动词。
905（1）在含有not的否定句中必须使用助动词，而且助动词通常要放在副词not的前面。
He has not come；or，He hasn't come．（在口语中多用后面这种紧缩形式，ain't为不规范形式）
He will not do it；or，He won't do it．
He cannot help it；or，He can't help it．
He is not here；or，He isn't here．
偶有不带助动词的否定句，但这种形式已经陈旧，如：
I know not．He looks not at anything ugly．
应说I do not know．He does not look at anything ugly．但I never know．He never looks，etc．是正确的。
否定疑问句可以（a）表示不耐烦情绪，（b）希望对方作肯定答复或（c）表示更大关切。
Has he not come? or，Hasn't he come?
Did you not know it? or，Didn't you know it?
Can he not help it? or，Can't he help it?
在重复前面的话时，主要动词常可省略。
John knows it，but Mary（名词）doesn't（或but not Mary）.
“Uncle can make a lot of money．”“But father can't（或but not father）.”
John knows it，but we（代词）don't（或用but not we，not us）.
“Uncle can do a lot of work．”“But I can't（或but not I，not me）.”
“Can he give up smoking?”“Of course，he can't（或用Of course not）.”
“May I enter?”“Perhaps you may not（或Perhaps not）.”
“Will he tell us the truth?”“Surely he won't（或Surely not）.”
在所有助动词中，只有do可用在祈使句中。
Do not play the fool．
Do not speak loud．
Do not hurt anybody's feelings．
有些词本身就有否定意思，这时（a）无须使用助动词，但有时（b）也可以和助动词一起用。
(a)I never said that．但是：I did not say that．
He scarcely saw it．
He hardly understands English．
He rarely tells lies．
He said nothing．
I have none．
(b)He has hardly begun his work．
You can never say that．
在一些特殊情况下，not可和一些动词一起用，无需加助动词。
“Is he angry?” “I think not（=that he is not angry）.”（但要说I don't think so．）
“Will they cheat him?” “I hope not（=that they will not cheat him）.”
“Can he get over the danger?” “I fear not．”
I know not what it is．
He cared not who said that．It mattered not．
I doubt not that he will fail．
He arrived yesterday，if I mistake not．
906（2）在疑问句中一般也必须使用助动词，而且助动词通常要放在主语及主要动词前面。
Has he come?
Can you do it?
Ought he to say something?
Did he come?
Do you know?
When did he come?
How can I do that?
如果主语为疑问词，则无须用助动词。
Who told you?
Which interests you most?
What accident happened?
下面是另一些无须加助动词的疑问句。
(a)有些陈述句可变为疑问句，只是句子用升调，结构完全不变。
He arrived yesterday?（=Did he arrive yesterday，as you or somebody said?）
“I love Mary（=Do you say I love Mary）?No，No!”
“She likes pretty dresses? Of course!”
(b)有些疑问句重复对方的话，也可大体保持原来的结构。
What you saw?（=You told me you saw something,but I don't remember or understand what you saw．）
Where he came from?
(c)构成从句的疑问句用陈述语句的语序。
I asked how John studied German．（比较：How did John study German?）
I am not sure whether you know it．（比较：Do you know it?）
(d)还有一些特殊结构，习惯上不加助动词。
How goes it with you?（How are you?）
How came it that he knew Mary?
What care I?（What do I care?）
What mattered it?（=What did it matter?）
What signifies it?（=What does it signify?）
What availed it?（What did it avail?）
907（3）在虚拟条件句中的连词省略时，主语前要加助动词。
Should all people think（=if all people thought）alike，this world would be unbearable．
Had Hitler（=If Hitler had）been born in 1960，he would have lived a different life．
Could I fly，I would fly immediately．
在虚拟条件句的主句中，通常也须用助动词。
If I were in your place，I would not do so．
If I were in Africa，I could do something．
If I had left a minute later，I might have died．
但在某些条件句中，不需加助动词。
If you are free，please come at seven．（祈使句）
In case you see him，ask him to wait for me．
If you move a step，you are a dead man．（使言语更有生气）
If you die，I die．
908（4）放在陈述句句末的简短问句（tag question）一般也需用助动词。这时陈述句若为肯定结构，后面问句多为否定结构，若为否定结构，后面问句多用肯定结构。这“问句”只要听者赞同，无须答案，说时用降调，句末用问号或句号。
David can come，can't he?（说话人希望对方作肯定回答）
He cannot come，can he?（说话人预计对方作否定回答）
John will do it，won't he?
John won't do it，will he?
He must speak up，mustn't he?
He mustn't speak up，must he?
Nobody should come，should they?
Nothing is wrong，is it?
I am right，aren't I（or ain't I，but not amn't I）?
He scarcely（否定副词）knows it，does he?
He never saw such a thing，did he?
He seldom said anything，did he?
You had better keep silent，hadn't you?
He ought to know it，oughtn't（or shouldn't）he?
There will be trouble，won't there?
在谓语中包含动词be时，有时不加助动词。
There is no problem，is there?
“She is beautiful.” “Yes，isn't she?”
“This task is not easy.” “No，is it?”
下面这些句子在非正式口语中，后面部分不包含助动词。
You have made a mistake，no（=haven't you）?
He is not happy，huh（=is he）?
You can come tomorrow，eh（=can't you）?
This is the first time you've come here，right（=isn't it）?
这类句子有时可用来寻求帮助或提出要求。
You don't（否定）know where's A Street，do you?
You couldn't lend me a hand，could you?
Wait a minute，can（or can't，could）you?（用在祈使句后）
Open the window，will（or won't，would）you?
909（5）在对别人的话做出反应时，有时也须用助动词（说时通常用升调）。
“I am tired．”—“Are you?”（陈述句为肯定句时，后面问句也用肯定结构）
“I don't see it．”—“Don't you?”（陈述句为否定句时，后面问句也用否定结构）
“Mary can play the violin．”“Can she?”
有时问句部分可用降调，带有吃惊或讽刺口吻。
“I won't go to school．”—“Oh，you won't，won't you?”
“Jane is angry with you．”“So she is，is she?”
有时用降调是表示衷心同意，后面部分就用否定结构。
“It is a lovely flower show．”（肯定）“Yes，isn't it!”（否定）
“She has become a lawyer．”“Hasn't she!”
有时陈述句和简短问句都用肯定结构或都用否定结构，来表示兴趣、惊讶、不快或怀疑等。
You are sleepy，are you?（肯定＋肯定）（兴趣）
She has got promoted，has she?（惊讶）
They don't like my dress，don't they?（否定＋否定）（恼怒）
It is eleven o'clock，is it?（怀疑）
He can repair cars，can he?（也可单纯提出问题）
910（6）助动词还可用来重复刚说的一句话，对它加以强调，这是英国人口语中常用的结构。在这类句子中，先行词却常放在代词之后。
They can do it，can those boys（or those boys can）.
They can't do it，can't those boys（or those boys can't）.
They can do it，those boys［can］．（助动词可以省略）
She must be angry，［must］my mother．
It is a bad place for young people，［is］that night club．
［He can］（主语及助动词省略）Speak six languages，Jim can．
［She is］Playing tennis，she is．
［She］（无助动词）Loves music，she does．
911（7）助动词还可用在“主要动词＋主语＋强调式助动词”这种结构的句子中。
While I may see beautiful things，see them I will．
While I can spend money，spend it I will．
If I must die，die I must．
He decides to go in February，as go I know he has to．
Yield he would not till he was killed outright．
Die he should not because he has a large family to maintain．
He wanted to go and go he did．
有时这种结构可成为一个独立的句子。
He said I did not study．Study I did．
He did not fail．Succeed he did．
912（8）以强调性的否定副词开始的倒装句也须用助动词。
Never can I understand what she wants．
Not in the least would he be disturbed．
Seldom has he been at home．
Hardly does he know his dangerous situation．
Only from newspapers do I learn about the world affairs．
在把否定的宾语提到句首加以强调时，也须用助动词。
Not a single word have I said about this trouble．
Nothing can he do．
No one else shall I love．
Very little care does he take of his children．
Never a cent have I spent on my wedding．
Hardly a grain of rice did he eat．
Only（=No more than）two persons did I meet in the desert．
有时一个普通状语放在句首时，也须在主语前放一个助动词。
For five hours have we waited．（这里一个不及物动词受到强调）
Most bitterly did he complain to me．
How happily did we live!（感叹句）
With what speed did the car run!
913（9）在强调的肯定句中也须用助动词（这时助动词须重读）。
I go there．
He come at once．
We tried our best．
I enjoy the trip．（没有别的助动词时可加do）
He like it．
I really（or actually，certainly or truly）do know him，but we rarely meet．（actually等副词可使强调更加明确）
forget me．（在祈使句中只能加助动词do）
take some．
be quick．
“May I sit here?” “．”
Do forget me．（you重读）
Do take some．
在强调的否定句中，也须用助动词（这时否定副词须重读）。
I will （or ）go there．
He can come at once．
John can understand．
“I do see it．”“But he ．”
“You can do that．”“But I ．”
“He did （or did）understand her．”
有时可以对主要动词加以强调，以形成对比。试比较下面两对句子：
I speak to him．（强调肯定要这样做）
I will to him．（But I will not write to him．）（在speak和write中强调speak）
He read．
He can ．（But he cannot write．）
有时加助动词do只是出于节奏上的考虑。
I do but jest with her．
She does but come to see me．
914（10）助动词还可用在省略句中来代表前句中的谓语，以避免重复。
“Will he come tomorrow?” “Yes，he will．”（will=will come tomorrow）
“Can you do something for me?” “I can't!”（can't=can't do anything for you）
“He is learning Japanese．”“Yes，he is．”
“Who knows the secret?” “David does．”
“John works hard．”“I don't think he does．”
“Lee is ready to help anyone who needs his help．” “He is．”
People think he is cunning and he is（or is so）.
“A friend told me he killed a detective．”“He did（or did so）.”
在这类句子中还可在前面加so或that，表示同意对方的说法，而略带惊讶。
“He has given up drinking．”“So he has．”or “That he has．”
“John leaves for Europe tomorrow．”“So he does．”or “That he does．”
“Mary must go at once．”“So she must．”
Lee is said to be a fool，and so he is（or that he is）.
“You have done everything evil．”“That I have，madam．”
of course，decidedly，surely，probably，或perhaps之类词或短语可加在这类结构前，表示“当然如此”“或许如此”等。
“He is too cunning for you．”“Of course，he is．”
“We can't ever say anything against our government．”“Surely，we can't．”
“It is said John is ill．”“Probably he is．”
“We shall win．”“Decidedly we shall．”
有时可用so来代表主语及助动词，在否定句中可用not来代替它们。
“Of course so．”
“Surely not．”
“Probably so．”
“Probably not．”
“Decidedly so．”
在对一个否定句表示赞同时，应当说no（不能说yes）。
“We can't make friends with such people．”“No，we can't．”（不是Yes，we can't．）
而对一个否定句表示不赞成时，应当说yes（不能说no）。
“We can't make friends with such poor people．” “Yes，we can．”（不是No，we can．）
“Mary isn't happy．”“But she is．”or “Yes，she is．”
915（11）在“so＋主语＋助动词＋（被省略及物动词）＋新的宾语” 这种结构中，助动词也是必不可少的。这时对前面句子的谓语加以重复，但把主要动词加以省略，只留下助动词。
“John will study this problem．”“So he will（study）many others．”（others为新的宾语）
“David has studied Algebra．”“So he has geometry and trigonometry．”
“The situation makes me worried．”“So it does everybody．”
在“新的主语＋助动词＋too”及“新的主语＋助动词＋not＋either”结构中，助动词也是必不可少的。
“He has done it．” “I have，too．”（I是一个新的主语）
“John can write a good letter．”“Mary can，too．”
“He has not done it!” “I haven't either.”
“John can never write a good letter．”“Mary can't either．”
在“so＋助动词＋新的主语”及“Neither（Nor）＋助动词＋新的主语”这类结构中，助动词也是必不可少的。
“He has done it．”“So have I．” or “So also have I.”
“John can write a good letter．”“So can Mary．” or “So too Mary．”
Kim lives abroad，and so do his relatives.
David is a fool．So is Jim．
David is a fool．So must his brother be．
“He hasn't done it．”“Neither have I．”“Nor have I．” or “No more have I．”
“John can't write a good letter．” “Neither can Mary．” “Nor can Mary.”or “No more can Mary．”
916（12）在“主语＋助动词（＋被省略及物动词）＋宾语”这种结构中，助动词也是必不可少的。这时用一个新的主语代替前句中的主语，用一个新的宾语代替前句中的宾语。
He fondled the cat as a mother（新主语）would（fondle）her child（新宾语）.
He discharged Zhang as his father had（discharged）others．
She let him go as a cat might a mouse．
He obeys Mary as a son should a mother．
I hate him as I do hell．
He can no more speak Russian that I can Greek．
在“So＋助动词（＋省略的及物动词）＋主语＋宾语”这种结构中也须用助动词。
You have helped me，and so have I you（=and I have helped you）.
He loves his mother dearly and so does she him．
“I love you．”“So do I you．”
c．助动词的读音
917 在口语中助动词有强弱两种形式。
强式（STRONG FORM） 弱式（WEAK FORM）
am[æm]
are[ɑː]
is[iz]
was[wɔz]
were[wəː]
be[biː ] 'm[əm][m]
're[ə]
's[z][s]
was[wəz][wz]
were[wə]
be[bi]
been[biːn] been[bin]
being[biːiŋ] —
have[hæv]
has[hæz]
had[hæd] 've[əv] [v]
's [əz] [z]
had，'d[əd][d]
do[duː]
does[dʌz]
did[did] do[du][də][d]
does[dəz][dz]
did[did] [dd]
shall[ʃæl]
should[ʃud] shall，'ll[ʃəl][ʃl][l]
should[ʃəd] [ʃd]
will[wil]
would[wud] will，'ll[l][əl]
would，'d[wəd] [əd][d]
can[kæn]
could[kud] can[kən][kn]
could[kəd][kd]
must[mʌst] must[məst][məs]
may[mei] —
dare[dεə] —
need[niːd] —
used[juːst] —
ought[ɔːt] —
918 在下面6种情况下助动词取强式读音法。
(1)作为一个单词。
The word “are” is an auxiliary verb．
“Shall” is understood in this sentence．
(2)在重读时。
I do know it，but I keep silent．
He was playing there，only you did not see him．
I can help him．I must help him．I will help him．
(3)放在句子末尾或意群的结尾时。
He has done all he can．
Has he done everything？Yes，he has．
I will pay him as I ought（to）．
(4)在句子开头时（这时也可读弱式）。
Have you seen it？
Can you come here？
Must I go now？
(5)向听众缓慢清楚说出时。
(6)在一些特殊的上下文中。
The bus is[iz] leaving（is在s，z，ʃ，ʒ等音后读强式）
He should [ʃud] come．（should在这里表示“ought to”）
They are eating ．（are在元音前读强式）
Dare I [dεərái]meet him？（Dare在元音前读[dεər]）
919 在其他情况下助动词均读作弱式。它常常和前面的代词或后面的not连起来读，如I'm（=I am），don't（=do not）。写出来时“'”表示有字母省略。这种连在一起读的形式称为紧缩形式（Contraction）。
— I'm（or am）[m] a student．（am在I后读弱式）
Am [əm] I right？（am放在句首时读弱式）
— They're（or are）[ə] mine．
You're（or are）[ə]right．
Are all of them wounded？（are在元音前的读法）
You're（or are）[ə] very kind．
—He's（or is）[z] here．（is在元音及浊辅音后的读法）
'Tis（=这是It is的特殊紧缩形式）my dog．
— My book's（or is）[s] lost．（is在名词主语后可写成's，但其他助动词则不行）
— He was [wəz] ill．
— Who were ill [wəril]？（were在元音前的读法）
— I have been waiting．（been可以强读，亦可弱读）
