Modal auxiliary verbs

We know that there are three types of auxiliaries in the english language. Among these, linking auxiliary verbs are generally used to describe subject, whereas, helping auxiliary verbs give additional information to the main verbs as per time, voice, and number. Apart from both, modal auxiliary verbs are used to express mood to state of mind.

Like linking and helping verbs, the ambit of functioning of modal auxiliaries is also vast. These are mainly used to convey possibility, request, necessity, permission, and advice. In this post ” Modal auxiliary verbs” I am going to present an overview of the all the modal auxiliaries.

Modal auxiliary verbs–

•What is  “PRAN” ?

•Possibility—May, Will, Could, Might

•Permission-May, Can


•Ability–Be able to, Can, Could

•Advice–Should, Ought to

•Requet–Can, Could, would, may

•Necessity, Obligation–Have to, Must

Let’s see an overview of all the modal auxiliary verbs


May, will, could, and might are especially used to express likeliness or possibility in present or future. It mere shows likeliness not certainty. However, not all four express same degree of possibility.

‘May’ express stronger possibility, whereas “can’ shows minor possibility. ‘Could’ is used in for past possibility. Besides, might expresses milder. In addition, will is preferred for certain prediction in future.

Permission–May, Can

Both express permission with varying degrees. Here, we need to understand permission at both ends.

If you are going to take permission; then, ‘may’ is preferred. But, to grant permission, usually ‘can’ is used ; for example, may I use your mobile?  Yes, you can. For deeper insight, you will learn in the next post.

Request–May, Could, Would

In order to make polite request, ‘could’ is usually preferred; on the other hand, ‘may’ is used for formal request.’Would’ is another modal auxiliary to express request.


Ability–Can, Could, be able to

There are two types of abilities- general and specific. In order to express strong ability ‘be able to’ is used after helping verbs.

For general possibility-may, could, can, and might are used. On the other hand, for specific possibility- ‘be able to’ is used after helping verbs according to the tense.

We use ‘can’ to show self ability, whereas, ‘may’ is indicates others abilities.

Advice–Should, ought to

Generally, should is used for common advice. It means that it is common everywhere for general advice. On the other hand, ought to expresses moral advice or obligations. It is highly useful in respect to moral duties or obligations.

Necessity or obligation–Have to, must

‘Must’ implies necessity, ‘but have to’ express compulsions to do something. Generally, ‘must’ is common in family interaction; on the other hand, ‘have to’ is more applicable in social relationship.

This is the general outline of all the modal auxiliary verbs. In the next post, you will learn about the specific application of modal auxiliary verbs. First of all, I am going to explain the correct use of will and would in a detailed way.

Linking and helping auxiliary verbs

Modal verbs for possibility

Corrective measures for bleeding biodiversity

Correct use of “but” and “yet”

Subordinating conjunctions

Understanding no sooner than