Compound and Complex sentences.

Ought to.

Ought is a modal auxiliary verb. There is no –s in the third person singular.

• She ought to understand. (NOT She oughts to …)


Ought is different from other auxiliary verbs. It is used with to

 We ought to respect our parents.
 We ought to help the poor.

Note that to is dropped in question tags.


 You ought to love your country, ought not you?(NOT…ought not you to.)

Must.

Must is a modal auxiliary verb. It has no –s in the third person singular.

• He must go. (NOT He musts go…)


Must is followed by an infinitive without to.

 I must get some rest.
 You must finish the report today itself.
 You must not tell this secret to anyone else.
 Little children must not be left unattended.


Questions and negatives are made without do.
• Must we go now?
• You must not worry.

Must has no infinitive (to must) or participles (musting, musted). And it has no past tense. When necessary, we use other words, for example forms of have to.
• He will have to start coming on time. (NOT He will must …)
• We had to cancel the project. (NOT We musted …)


Meaning

Must indicates that it is necessary or very important that something happens. If you say that you must do something,you mean that you have a definite intention to do something in future.

 I must get my hair cut.
 I must stop smoking.
 We must get someone to repair the roof.

If you tell someone else that they must do something, you are emphasizing that it is a good idea for them to do that.
 You must stop lying.

Should.

Should is a modal auxiliary verb. There is no –s in the third person singular.

• He should be here soon. (NOT He shoulds …)
• You should mend your ways.


Should is followed by an infinitive without to. Questions and negatives are made without do.
• You should go now.
• Should I go now?
• No, you should not.


Note that should is the past equivalent of shall in indirect speech.
• They asked, ‘What shall we do?’
• They asked what they should do.



Uses
To express obligation

Should is often used to talk about duty or obligation. It can also be used to say or ask what the correct or best thing to do is.

• You should tell the truth.
• If you are not feeling well, you should consult a doctor.
• There should be an investigation into the cause of the accident.

Note that should is not as strong as must.

Shall.

Shall is a modal auxiliary verb. It is followed by an infinitive without to. Shall has no –s in the third person singular.
• I shall be home soon.
• We shall invite them to dinner.
• I think I shall send him a wire.
• We shall be leaving for Delhi tomorrow.


Questions and negatives are made without do.
• Shall we report this to the police? (NOT Do we shall…?)
• No, we shall not. (NOT We don't shall.)

With the first person

In the first person shall expresses simple futurity. It is used to show the strong possibility or near certainty of an action or event which is to take place in the future.

With the second or third person

In the second and third persons shall may express a command.
• You shall go at once. (= You are commanded to go at once.)
• He shall carry out my instructions. (= He is commanded to carry out my instructions.)


Sometimes it is used to make a promise.
• He shall be given a present if he passes this year.


Shall may also express a threat.
• You shall regret this.
• They shall pay for this in due course.

Note that shall is becoming increasingly less common in Modern English. Instead of using shall in the second and third person to indicate a command, promise or threat, people often use other verbs and expressions.

Will.

Will is a modal auxiliary verb. It is followed by an infinitive without to. There is no –s in the third person singular.

• She will come. (NOT She wills come.)
• I will do it.


Questions and negatives are made without do.
• Will you come with me? (NOT Do you will …)
• I will not let him go.


Uses
To express simple futurity
Will is used to talk about future events that you are certain about or things that are planned.
• Ann will be 10 years old next month.
• There will be trouble if he catches you stealing his flowers.
• The train leaves at 9:30, so we will be home by lunchtime.

Might.

Might is a modal auxiliary verb. It is followed by an infinitive without to. There is no –s in the third person singular.

• It might rain this evening.
Questions and negatives are made without do.
• We might not be home before evening.


Might does not have infinitives or participles. When necessary, we use other words.

Might is used to talk about possibility, and to ask for and give permission.

We often use might to say that there is a chance that something is happening, or that there is a possibility of it happening.

• It might rain this evening.
• She might come.

May.

May is a modal auxiliary verb. There is no –s in the third person singular.

• She may be here soon. (NOT She mays …)



May is followed by an infinitive without to.

• You may be right. (NOT You may to be right.)
• He may come.


Questions and negatives are made without do.

• May I come in, please? (NOT Do I may come …)
• He may not come. (NOT He do not may come.)

May does not have infinitives (to may) or participles (maying, mayed). When necessary, we use other words.

May is used to talk about possibility, and to ask for and give permission.
• It may rain this afternoon.
• May I play carroms, mummy?
• Yes, you may.


Possibility
May is used to talk about the chances of something happening.

• I think it is going to rain. You may be right.
• There may be a strike next week.
• Where is John? He may be out shopping.


May well is used to suggest a strong possibility.
• I think it is going to rain. You may well be right.


May is not normally used in direct questions about probability.
• Are they likely to help us? (BUT NOT May they help us?)


But note that may is possible in indirect questions about probability.
• May we not be making a big mistake?

Can.

Can is a modal auxiliary verb. It is followed by an infinitive without to. There is no –s in the third person singular.


 I can swim.
 She can dance. (NOT She cans …)
 He can run a mile in two minutes. (NOT He can to run…)
 She can play soccer very well. (NOT She can to play soccer…)



Questions and negatives are made without do.

 Can you speak English? (NOT Do you can speak English?)
 I can't swim. (NOT I don't can swim.)
 You can't fool him. (NOT You don't can fool him.)

Modal auxiliaries.

The verbs will, would, shall, should, can, could, may, might, must, ought, dare and need are usually called modal auxiliaries. They are used with other verbs to express actions, events or situations that exist only as conceptions of the mind - permissions, possibilities, certainty, ability, wishes, obligations etc. They may also express simple futurity.

• I can run.
• She will go.
• I must read now.
• Should I mention them?
• She might eat.



Modal auxiliaries have three common characteristics.


1. They are never used alone. A principal verb is either present or implied.
• I can fly a plane.
• He should behave.
• Will you go? Yes, I will (go).



2. Modal auxiliaries have no –s in the third person singular.
• I can work.
• She can work. (NOT She cans …)
• I may pass.
• He may pass.
• They may pass.



3. Modal auxiliaries do not have infinitives (to may, to shall etc.) or participles (maying, shalling, shalled etc.). You cannot say to shall, to must or to may.

Primary auxiliaries.

Be, do, have and their various forms are called primary auxiliaries.

1) Be is used with other verbs to make progressive and passive verbs forms.

• I am writing.
• He was punished for lying.


2) Do is used to make questions, negatives and emphatic forms of non-auxiliary verbs.

• Do you know where Paul lives?
• I don’t know.
• Do sit down.


3)Have is used to make perfect verbs forms.

• I have completed my work.
• She has acted in a movie.
• They had forgotten to send the mail.


Primary auxiliaries merely help to express statements of fact.
• She is writing.
• I am working.
• You have done wrong.
• He did not come in time.
• They have arrived.


Note that be, do and have can also function as principal verbs. They are called auxiliaries only when they help other verbs to form their tenses and moods.
 You were wrong. (Principal verb)
 You have done wrong. (Auxiliary verb)
 She is a good singer. (Principal verb)
 She is singing. (Auxiliary verb)