The General pattern of Modal Auxiliaries in a sentence is
S + Modal Auxiliaries + V1 + C
The uses of WILL :
1.1. in future tenses. (see Tenses)
1.2. to express a REQUEST :
e.g. A : Hey… what’s the matter with you? Not feeling well, huh?
B : Will you get me some aspirin?
A : Sure. Here it is. Get some sleep for a moment then.
B : Thanks.
1.3. to express a PROMISE (with first person)
e.g. A : Don’t you remember that today is father’s birthday ?
B : Of course, I do.
A : So don’t forget to go home earlier!
B : I will.
1.4. to express THREAT (with first person)
e.g. A : I need some points in these three lessons in order to be promoted.
B : What do you want from me?
A : Let me know your answers in the final test.
B : But …
A : I will tell your shameful secret to everyone and send you away from my club.
Another form of WILL is BE GOING TO. It is used when we need two modal verbs in our sentence.
e.g. They may be going to find the other facts. (NOT : They may will find the other facts)
He must be going to observe it in his laboratory.
BE GOING TO is used in future tense also. ( see TENSES )
The uses of WOULD
2.1. in past future tenses ( see TENSES )
2.2. to express an INVITATION or OFFER
e.g. A : Hey… what are you up to these days?
B : Just fine. And you?
A : Nothing to complain of. Would you join us? We have a small party to celebrate my graduate.
B : I wish I could but I have something to do here. Oh .. congratulation, anyway!
A : Thanks.
2.3. to express a REQUEST ( more polite than WILL ) :
e.g. A : Would you look after my pets? We will be out of the town for two days.
B : I will.
A : Sorry to trouble you.
B : Don’t worry.
The other forms of polite request are :
– Would you like to look after my pets?
– Would you mind looking after my pets?
– Would you care to look after my pets?
* WOULD LIKE = WANT in these cases :
e.g. I would like to see some more ( more polite ) = I want to see some more
Would you like to speak to him? = Do you want to speak to him?
* But see this comparison :
A : Would you like to have some tea with us? ( an invitation or offer )
B : Thank you. I’d love to.
A : Do you want to have some tea? ( a usual question )
B : Yes, I do / No, I don’t
* WOULD RATHER / SOONER ( to show preference )
e.g. He would rather stay here than go with you = He prefers staying here to going with you.
He would rather eat some sea food than chicken = He prefers some sea food to chicken.
The uses of SHALL :
3.1. The same as WILL, it is used in future tense (see TENSES)
3.2. to express a REQUEST FOR ADVICE OR ORDER
e.g. A : Shall I apologize for not calling her up last night?
B : Why not?
A : But I doubt that she won’t accept it.
B : You haven’t tried it, have you?
3.3. to express an OFFER
e.g. A : Sorry that I make you wait for some minutes.
B : Never mind.
A : It is the busiest day. There’s so much work I have to finish.
B : Shall I help you go over these reports ?
A : I appreciate your help, anyway, but I’ll manage it by myself.
3.4. to express a SUGGESTION
e.g. A : There is a speech contest held by the students from English department.
B : Then, what?
A : Shall we take advantage of this chance ?
B : Sounds great !
The uses of SHOULD :
4.1. It can replace SHALL in offer, suggestion and request for advice or order.
4.2. to give advice / to say what we think it right or good for others to do
e.g. A : You shouldn’t depend on him.
B : But he promised to come and help me. Do you think he will keep his word ?
A : I am not sure. I know him for a long time, as I told you. He’s not a good guy.
4.3. SHOULD with WHY and HOW :
4.3.1. to express INABILITY TO UNDERSTAND
e.g. How should those birds be able to understand the trainer’s command?
Why should he fire the most faithful employee?
4.3.2. to express IRRITATION or ANGER
e.g. A : Finish it now !
B : Why should I ? You have no right to order me !
A : What are they talking about ?
B : How should I know it ? It’s not my business and yours, too.
5. OUGHT TO
Its use is the same as SHOULD no. 2
The uses of MAY :
6.1. to express PERMISSION :
6.1.1. to give permission ( affirmative )
e.g. A : Why do you ask for a dog to that man?
B : I will take care of it.
A : Do your parents permit you?
B : Yes, I may keep a pet in my house if I promise to take care of it myself.
6.1.2. to ask for permission ( interrogative )
e.g. A : Excuse me Sir, may I interrupt ?
B : Yes, come in.
A : Someone urges to meet you though I have told that you are having an important meeting.
B : Ask him to get in!
6.1.3. to refuse permission / PROHIBITION ( negative )
e.g. In the school laboratory,
A : We will use some chemical substances which cause our skin burnt if they touch it. So, you may not make a joke here. Don’t forget to use the gloves.
B : Yes, Sir !
* In past and perfect tenses we usually use BE ALLOWED TO but in indirect speech we can use MIGHT.
e.g. I was allowed to keep a pet when I was a child. (= My parents allowed me / gave me permission to keep…)
They have been allowed to use their rights in this election.
She said,” He may have three days off “.
She said that he might have three days off.
BE ALLOWED TO is also used if we want to use two modal verbs in our sentence.
e.g. You will be allowed to leave early if everything is finished. ( NOT : You will may leave …)
The journalists must be allowed to cover up this trial.
6.2. to express POSSIBILITY (in future or present and used in positive and negative only) :
e.g. A : Look at the two young men standing by the pool!
B : What’s wrong?
A : They may be the members of FBI.
B : How do you know ?
A : I often see them where our boss is.
6.3. to express FAITH or HOPE
e.g. A : Listen ! I have got the promotion!!
B : Really? Tell me.
A : When I gave my last proposal this morning, Mr. T told that I should move to the room next to his.
B : Oh … I’m glad to hear that. May the great success come to your life! Congratulation!
A : Thank you.
The uses of MIGHT :
7.1. as past form of MAY used in indirect speech. (see MAY)
7.2. to express POSSIBILITY (smaller than MAY)
e.g. A : They aren’t familiar to one another, so it might be easy for them to work in group.
B : I don’t think so. Children are always able to adapt to their new environment and friends.
A : As those new employees have just graduated, they might be able to handle this unit well.
B : I agree with you. They don’t have enough experience.
The uses of CAN :
8.1. to express ABILITY (in present or future)
e.g. A : Hey … can you slow down this car ? It’s too slippery.
B : Don’t worry, I can control it well. Don’t you remember that I am the best motorist ?
A : Don’t be so proud of yourself.
* BE ABLE TO is another form of CAN. We use it when there are two modals in our sentence.
e.g. Don’t worry, the thief won’t be able to break up this box. ( NOT : the thief won’t can break up …)
My mechanic may be able to fix it. ( NOT : my mechanic may can fix it )
Every student should be able to think critically. ( NOT : every student should can think …)
He must be able to solve it by himself. ( NOT : he must can solve …)
* BE ABLE TO is also used in PAST and PERFECT tenses.
e.g. She has been able to calm down those people.
He was able to improve his ability by himself.
8.2. to express POSSIBILITY ( affirmative only ). It is different from possibility expressed by MAY.
8.2.1. it means that it is possible if circumstances permit.
e.g. A : I wish that he isn’t late. If he misses the interview, he will lose his chance to get what he is eager to reach.
B : I think he can get there in about two hours because the bypass has been opened. So, he will have 30 minutes to prepare himself.
8.2.2. theoretically it is possible.
e.g. A : Please, decrease the temperature quickly! It’s more than normal.
B : Why?
A : The pipe can burst out if it is overheated
8.2.3. to give information about the characteristics of persons or things.
e.g. A : What do you think about her?
B : Why do you ask me?
A : You are her cousin, aren’t you?
B : As far as I know, she is a sensitive girl. She can keep herself away from anyone who hurts her, even her boyfriend, for a long time.
8.3. to express PERMISSION (in affirmative or question only and less formal than MAY)
e.g. A : Can I have some more? (ask for permission)
B : Hey … you are on a diet, aren’t you?
A : Not in such situation.
B : Hm … that’s why you never lose your weight.
A : Listen! I have got good news for us. We can collect our assignment next week. ( the speaker doesn’t have an authority to give permission)
B : How do you know?
A : The teacher called me this morning and told that there would be a meeting tomorrow , so the discussion would be cancelled.
8.4. to express an OFFER
8.4.1. in positive
e.g. A : You look so confused.
B : It will be my turn to answer after her but I haven’t got the answer yet.
A : You can use my work
B : No, thank you. The teacher will know that it is yours.
8.4.2. in question
e.g. A : How about the preparation?
B : I don’t think that we can finish it today. We still have to contact Mr. D for accommodation.
A : Can I call at his office on the way to my house? I will ring you before dinner.
B : That’s nice of you. Thank you.
A : Don’t mention it.
8.5. to express a REQUEST (less formal than WOULD)
e.g. A : I am still confused about this point. Can you explain it to me?
B : Sure, but I can’t do it right now because I will have a test. How about in the afternoon?
A : In your house ?
B : Of course, what’s the matter?
A : Oh .. I am just afraid that some one will be jealous.
B : Don’t be worried, I have no special one.
the uses of COULD :
9.1. to express PAST ABILITY (= WAS/WERE ABLE TO)
e.g. A : Have you visited him?
B : Not yet. How is he?
A : He is getting better physically, but it seems that he loses his memories. He could /was able to mention the formulae of solutions accurately and spontaneously, but now he has to think hard to find them.
9.2. to express PAST PERMISSION (= WAS/WERE ALLOWED TO)
e.g. A : Do you remember what we always did in this park when we were children?
B : Yes, we could come here every afternoon to play with our friends.
A : But now, look at the sign! We can’t even enter it.
9.3. to express POSSIBILITY :
9.3.1. For affirmative or interrogative sentence, it is the same as MAY / MIGHT.
e.g. Would you open the door? It could / may / might be your friend.
9.3.2. there is a difference between MAY and COULD in negative.
e.g. He couldn’t have an answer. (It is impossible that he has an answer )
He may not have an answer. ( perhaps he doesn’t have an answer )
9.3.3. COULDN’T ( or CAN’T ) can be used for NEGATIVE CONCLUSION / CERTAINTY ( contrasted to MUST ).
e.g. A : She never comes late.
B : She may forget it.
A : I don’t think so, I know her. She always keeps her word. She couldn’t / can’t have someone to take her. I’ll phone her for sure.
9.4. COULD YOU … ? can also be used for introducing a request as an alternative to WOULD YOU…?
e.g. Would you / could you do me a favor ?
10. MUST, HAVE TO and NEED
The uses of MUST :
10.1. To express obligation :
|OBLIGATION||ABSENCE OF OBLIGATION||NEGATIVE OBLIGATION|
will have to
won’t need to
won’t have to
don’t need to
don’t have to
|Past||had to||didn’t have to||didn’t need to|
10.1.1.In affirmative, MUST is used in present and future. For other tenses, we use HAVE TO although it can also be used in present and future (with WILL).
See the difference between MUST and HAVE TO in present or future :
e.g. A MOTHER to HER SON : “ When you are thirteen next month , your own room will have been finished so you must do your room yourself . Besides, you have been grown up. Be responsible to yourself “. (internal obligation or the speaker’s obligation)
A MOTHER to HER SON : “ You will have to do your room when you have been in college dormitory as the rule says. You can’t pay someone for it .” (external obligation or the rule of the dormitory)
* In the first person, HAVE TO is used for habits while MUST for an important or urgent obligation.
e.g. A : Why are you in a hurry?
B : Ditto hasn’t come yet. I must call him up to tell that they will arrive in 15 minutes. He is the MC.
A : What time is it?
B : 19.45
A : Oh… my GOD, I have to tell my parents that I will be late for dinner.
B : Do you have to do it?
A : Yes, every member of my family will do it. It’s our habit whenever we will go home late in order that they aren’t worried about us.
10.1.2. NEED can be treated as an auxiliary and used mainly in negative and interrogative. It has no past form, and usually used for present or future. ( see the table above )
e.g. A : You needn’t do it in a hurry. I have put off the meeting till next week. ( The speaker has an authority to state that an action is unnecessary )
B : Yes, Sir!
A : Can I borrow your dictionary?
B : What for ?
A : to finish the vocabulary task ! Do you forget about it?
B : Are you daydreaming ? Don’t you remember that it’s always collected at the end of a month? We still have much time. You don’t have to / don’t need to do it now. ( for habit or negative external obligation )
A : You must not do it in a hurry because if you are careless and make a mistake, it will explode. (negative internal obligation / prohibition )
B : but we have limited time, Sir!
A : Don’t worry, I will ask Mr. D to help you! Our success depends on you, so do be careful !
10.1.3. There are some possible answers in interrogative using MUST,
|QUESTION||POSITIVE ANSWER||NEGATIVE ANSWER|
|Shall I have to?||Yes, you will||No, you won’t|
|Does he have to go?||Yes, he does||No, he doesn’t|
|Need I go?||Yes, you must||No, you needn’t|
|Must I go?||Yes, you must||No, you needn’t|
e.g. A : You must supply them with the correct information.
B : Must I supply them with the data too?
A : No, you needn’t.
B : The correct information usually includes the correct data, doesn’t it?
A : Yes, but not in this case. You should understand that sometimes we don’t have to give anything clearly to anyone who wants to know about us.
10.2. to express a POSITIVE CONCLUSION / CERTAINTY :
e.g. A : Look, it seems that there is no vacant seat for the three of us.
B : I don’t think so, because Mr. D told me that he still had 30 % of the tickets left.
A : So, there must be some seats vacant in the front.
* See the difference between MUST and MAY or MIGHT :
A : What should I give her? She refused all I gave to her.
B : Give the food which is cooked by yourself. She may accept it because she likes your cooking.
A : I have, but still she doesn’t touch it.
B : (thinks for a moment) Ha … it must work out.
A : What’s in your mind ?
B : You don’t need to give it yourself. Let her boyfriend do it.
A : You are a smart man.
As an auxiliary, it is usual in negative or question form.
Negative present / past He does not dare / dares not
He did not dare / dared not
Interrogative present / past Does he dare? / Dare he?
Did he dare? / Dared he?
e.g. He doesn’t dare (to) say anything after that quarrel.
He dares not (to) say anything after that quarrel.
Did he dare interrupt them?
Dared he interrupt them?
* HOW DARE(D) HE /YOU / THEY ?
expresses indignation or anger.
e.g. How dare you open my letter without my permission ? (= I’m angry with you for opening it)
How dared he make a fool of her in front of the audience last night ? ( = I was really indignant of his behavior )