Modal Auxiliaries

Some words ought to be as a remedy, some may be as a medicine.

They help verbs. They express a wide range of meanings:
Ability, possibility, permission, necessity… Most of the
modals have more than one meaning.

Can – could – may – might – should – would – had better
will – must, Have to – ought to – have got to.
The simple form of the verb follows all of them.

Examples:
She should work harder.
I have got to travel this summer.
She has to do her homework herself.
Would you speak more slowly please?
You had better see him after your conflict.
Shouldn’t you save a little money for a rainy day?
You must not wait like this!
May I have this pen to write down some words?
You’d better not come late!

Can expresses ability in the present or future.
	Can = is able to (present) 
	=  Will be able (future)
The negative of can is: Can’t = cannot = can not
The past form of can is could. Its negative is couldn’t = could not.

Could express the ability in the past.
Could = was able (past)

Examples:
I can buy a screwdriver at a hardware store. But I cannot use it. (Present)
She could speak English, but she couldn’t write it. (Past)

 
May is usually used in formal situations, can is used in 
informal situation.

Examples:
You may borrow my car when you come.
Can I borrow your book?

 
4.1. May I, could, Can I, Might I? : “ I ” is the subject
We use those modals to ask polite questions. The questions ask for
someone’s permission. 

May I is more formal than could I. Please is often included
in questions.

Might I is less frequently used. But it has the same meaning
and usage as may I and could I.

Can I is sometimes used informally to request permission,
especially if the speaker is talking to someone fairly well known.

 
4.2. Would You, Will You, Can You, Could You? :“ You ” is the subject
The meaning of would you and will you in a polite question are the same. But would 
You is more common and polite than will you. However, the degree of politeness is 
determined by the speaker’s tone of voice.

Would you and could you have the same meaning. The difference is slight:
Would you = do you want to do this please?

Could you = do you want to do this please, and is it possible for you to do this?

Can you is sometimes informal.

Typical responses:
Yes, I’d be happy to.
Yes I’d be glad to.
Certainly.
Sure. (Informal)

Do not use May you. Or Might you? (For a polite question)

4.3.  Would you mind
4.3.1. Asking permission
Examples:
Would you mind if I close the door? (Informal spoken English)
Would you mind if I closed the door? (Formal)
“Would you mind if I”  is followed by the simple past.
The meaning of the question is: 
May I close the door?
Is it all right if I close the door?
Will it cause you any trouble or discomfort if I close the door?

Typical responses:
No.
No at all.
Unh-unh = No.

4.3.2.Asking somebody else to do something
Would you mind closing the door? 
"Would you mind if`" I is followed by a gerund.
The meaning is:
I don’t want to cause you any trouble, but would
You please close the door?
Would that cause you any inconvenience?

Typical responses:
No, I’d be happy to
No at all, I’d be glad to.
Unh-unh = No.

 
They mean: This is a good idea. This is good advice.
The negative forms are: shouldn’t – had better not. 
Ought to doesn’t have the negative form.

Should and ought to have the same meaning. 
Had better is close to should and ought to. But had better is stronger.
Basically, had better means: This is a very good idea.
Often, had better implies a warning or a threat of possible bad consequences.

Had, here, is not the past of have. It’s used as part of an idiom. 
It is used in the present and the future as well.

Ought to = otta
Sometimes in speaking, had is dropped: 

Examples:
You better stay home.
You should stay to listen.
You need your sleep. You shouldn’t stay up late.
What should I do now?
I had better stay home.
She had better not smoke. 
She’d better save extra money.
He ought to come in time.

 

Should have + -ed (past participle) (Not: should + present perfect)
Examples:
He should have waited a little bit.
She should not have wasted all this time.
The past form of ought to is ought to have + -ed
Had better has no past form.

 
In conversational:
Should have = shoud’ve or shouda
Should have not = shoudn’t’ve = shoudn’t’a 

 

 
Have is a verb which may be conjugated.
Must means that something is very necessary. There is no 
other choice. It’s a strong word.

Have got to is informal.
Have to = hafta
Has to = hasta
Got to = gotta

Examples:
They have got to go now (only in spoken English)

In conversational:
I’ve gotta go now or I gotta go now.


He has to leave now. 
He had to study yesterday.
He must do some good deeds.

 
The past form of both must and have to is had to.

The meaning of the negative forms of must and have to are different:

Must not = mustn’t = prohibition = Do not do this!
Do not have to = Lack of necessity = Not necessary.

Examples:
We don’t have to believe him.
Children, you mustn’t see that!

  

They are used to give commands, make polite requests and give directions.
The difference between command and directions lies in the speaker’s tone
and voice + the use of please.

We use a simple form of the verb.
Examples:
Open the door (order, command)
Please open the door (polite request)
Walk two blocks down this street, turn left and walk 
	three more blocks. (Directions)

Negative form: Don’t + the simple form of the verb
Don’t close the door.
Don’t close the door please.
Please don’t close the door.

 Sometimes won’t you is added as a tag question to make a polite request.
Come on please. Won’t you?

 

 

Let’s (do something) and why don’t we (you and me – you and us)
Are used to make suggestions about activities. Let’s = Let us

Why don’t you (do something) is used to make friendly suggestions,
To give a friendly advice.
Examples:
Let’s go to walk
Let’s not go!
Why don’t we go to the park? = Let’s go to the park (the same meaning)
Why don’t you use your car?
Why don’t I do it myself?
Why doesn’t she stay?

 We also use Shall in questions to make suggestions.
Sometimes shall we? Is used as a tag question after Let’s. 
More informally, okay is used as a tag question.

Shall I stay a moment?
Shall we come over at nine?
Let’s talk, shall we?
Let’s talk, okay?

We use DO as an auxiliary in affirmative sentence to make the 
verb stronger or to emphasize what we are saying.

I don’t have an answer. But I do have a question.

We use also DO for emphasis in a sentence with a tag question when we 
want to make sure that we have the right information.
Examples:
She does come over, doesn’t she?
They did tell us to be here, didn’t they?
 
Emphatic DO frequently occurs with never.
He never did learn how to be patient. And he still doesn’t.

May and might express possibility in the present or future.
They have the same meaning.
Examples:
They may be absent today.
She might come after her test.
Maybe she comes after her test.
(maybe = perhaps is an adverb)

The negative forms are: May not, might not.

May and can are used for Permission. 
May is more formal than can.

May not & cannot are used to deny permission.
Examples:
You cannot have a candy. 
You may not be in this place.

Must expresses a logical conclusion (and probability). But we don’t 
know for certain.
We base our logical guess on the information that we saw.
Examples:
He is yawning. He must be sleepy.

13.1. Progressive form:
Modal + be + -ing (in progress right now)
Example:
At this time, she May (might) be sleeping. You had better
Not disturb her.

13.2. Past form:
Modal + have + -ed (past participle) (in the past)
Examples:
He doesn’t come yet. He may (might) have forgotten this appointment.
Or maybe, he must have lost something.

Must, here means probability. The past of must is had to when it 
means necessity.

13.3. Past progressive form:
Modal + have been + -ing (past participle) (in progress at a time in the past)
Examples:
When we went to pick him up yesterday, we didn’t find him.
	He may (might) have been working. 
He must have been studying because he has a lot of exams coming soon.

 
 

Should also, as ought to, express expectation. In this case, 
Should = ought to = will probably.
Examples:
He looks like rich. He should do well.
They should get my e-mail tomorrow. 
Let’s go to the lecture. It ought to be interesting.

The past form expresses the expectation that something did not occur.
Examples:
We waited for him a long time. But he didn’t arrive. 
We should have seen him by now.

 

We use those modals to ask polite questions. The questions ask for
Someone’s help or cooperation.

"Can I" is less formal than the others.
Examples:
 Could you please open the windows?
Will you come to help us this afternoon?
Can you pick this key up for me please?
Would you answer me without delay please?
What could it be?

 

In addition to could can mean past ability, Could also express possibility 
in present and future like May and Might.
Examples:
He may drive = He might drive = He could drive (=Possibility)
He could be sick (present)
He could start raining any minute (future)

The passive form: Modal + be + -ed (past participle)
Examples:
Franck couldn’t be reached at his phone number.
He can’t be reached at his phone number either.
He May be reached at another one.
He should be reached at this one.
He had better be reached at this one.
He must be reached at the last one. He has no choice.
He ought to be reached at another one.
We have to be reached at the same phone number.

The past-passive form: modal + have been + -ed (past participle)
Examples:
He should have been visited yesterday
He must have been rewarded last week.
He might have been reached this morning.
She ought to have been visited last night.

We use:
Prefer… to, like…better than 
would rather… than.

I prefer NOUN to NOUN
I prefer verb -ing to verb -ing

I like NOUN better than NOUN
I like verb -ing better than verb -ing

"Would rather" means prefer.
I would rather = I’d rather
I would rather write than sleep.
I’d rather have an apple than (have) a peach.

Immediately the simple form of a verb follows rather and than.
If the verb is the same, it does not have been repeated after than.

In a polite question, would rather can be followed by OR to offer
someone a choice.      
Example:
Would you rather have an apple or an orange? 

The negative form is would rather not.
Example:
She would rather not see him.

The past form: Would rather have + -ed
Example:
This speech was boring; I’d rather have stayed home.

The progressive form: would rather be + -ing
Example:
I would rather be sleeping than (be) watching TV.

 

Would can be used as used to when the action was repeated regularly in the past.
If the situation existed in the past without repetition, would is not used.
Example:
I would read a lot books in the university.

Would is used to give a soft statement:
Examples:
I want to understand (strong)
I would like to borrow your car. (Soft and polite)
I prefer stay home. (Strong and definite)
I would prefer stay home (soft)

Would is frequently used in a response to a polite question. 
I’d be happy (glad, pleased) to help you 

I’d appreciate hearing from you soon: It is a polite way of saying 
“Please write to me soon.”