The verb that helps the main verb of a Sentence to express its meaning clearly and completely is known as Helping verb. This helping verb is otherwise known as Auxiliary verb. Modal verbs in English is divided into 2 types Primary Auxiliary & Modal Auxiliary.
Use of Modal Verbs (M.V.) & Helping Verbs (H.V.)
(i) I work (M.V.) in a junior college.
(ii) We are (H.V.) playing (M.V.) football.
(iii) They should (H.V.) obey (M.V.) their parents.
(iv) Dolly must (H.V.) do (M.V.) it.
(v) Muna & Mama have (H.V.) made (M.V.) this project.
It is further classified into two groups Primary Auxiliary & Modal Auxiliary.
(1) Be group Aux (Be – Was, Is – Was, Am – Was, Are – Were)
(2) ‘Do’ group Aux (Do, Does – Did)
(3) ‘Have’ group Aux (Has/Have – Had)
Examples of Modal Verbs
- Will, Would (Future time reference, making request, offer to help).
- Shall, Should (Future time reference, making suggestion, duty, asking for permission).
- Can, Could (Ability, making polite request, asking permission, strong possibility).
- May, Might (Possibility, making polite request, asking formal permission).
- Must (Certainty).
- Ought to (Duty & obligation).
- Used to (Past habit).
- Need (Necessity).
- Dare (Courage).
Different modals are used in different ways & in different meanings to express various ideas clearly and completely.
A number of modals such as can, could, will, would and may are used to make requests. But each of these modals is used in a slightly different way from the others.
Can is informal, while could is more formal & polite. Will is used to make request when we don’t need to be particularly formal and polite.
But would you or would you mind is used when we want to be more polite or formal. May is rather formal.
Asking for and granting permission
Modals such as can, could, may, would are used for asking for and granting permission. Can is used, in questions, for asking permission. It is also used, in statement form, to grant or give permission to someone. Can is used in informal situations.
But could is used in more formal situations or when the speaker is not sure whether permission will be granted. Could is never used to give permission to someone.
May and would you mind are used in questions to ask for permission in formal situations, when the speaker is even less sure of getting permission or feels that permission is likely to be refused. It is also used in statements to give permission.
Making an offer to help
Modals such as will, would, shall, can, could etc. are used to make an offer to help.
Will, shall and can are used in informal English to offer help to someone. Will is used only in statements, but shall and can are used in questions as well as in statements.
But could and would are used in questions as well as statements to offer help in more formal situation.
Making a suggestion
Modals such as shall, can, could let’s, how about etc. are used to make suggestion.
Expressing Ability to do something
(can, Be able to)
Can is used to show that somebody has the ability to do something. But “Be able to” can also be used for this purpose. When can is more usual, Be able to is formal.
Sometimes could is used to refer to the general ability to do something in the past. But was able to, were able to is used to refer to do something in a particular situation.
(May & can)
May be used to express a specific possibility while Can is used to express a theoretical or general possibility.
Indicating present or future possibility
(May, might or could)
May, Might & Could are used to the present or future possibility. Might is normally a little less sure than may & could is less sure than may or might.
Referring to possibility in the past
(May, might, could with present perfect form)
We normally use may/might/could together with some verb in the present perfect form to talk about possibility in the past.
Ex. – The other teams weren’t good, so our team could have won the match.
Making A deduction
(Using must have/can’t have)
“Must” is used here to make a deduction, that is, to come to a logical conclusion on the basis of evidence which is available. The use of must shows that the speaker is quite sure that what he/she says is correct.
Can’t is the negative counterpart of must. The use of can’t, in this case, shows that the speaker is very sure about some negative conclusion which he/she reaches.
The use of must have & can’t have shows that the speaker has made a deduction about something that happened in the past.
(Using should/Ought to/had better/Be supposed to)
Should & Ought to are used to ask for as well as give advice. Ought to is preferred when the advice is given by someone in authority.
Had better indicates a strong recommendation, made for particular situation.
Should have ………… & ought to have ………… are used to show that some one didn’t do something that was advisable.
Expressing Obligation or necessity
(Using must, Have to/ Had to/have got to)
Must & have to are used to express obligation or necessity. We normally use must when the authority comes from the speaker. “Have to” is normally used when the authority comes from someone other than the speaker. We use had to when talking about past obligation or necessity. Have got to is sometimes used instead of have to to talk about obligation or necessity, at it is more informal.
(Using mustn’t, Needn’t, don’t have to)
We use mustn’t to prohibit somebody from doing something. We use needn’t, does/don’t have to, does/don’t need to when it is not necessary to do something.
Expressing Absence of obligation or necessity
(Needn’t have, didn’t need to, didn’t have to )
Needn’t, didn’t need to are used to indicate that there was no necessary or obligation to do something.
The use of didn’t need to indicate that the person concerned knew before hand that a certain action was not required & so it was not done. The use of didn’t have to indicates that the person realized that the action was not required only after it had already been performed.
Didn’t have to can be replaced by Needn’t have.