Modal verbs are a unique category of verbs in English, they have their own rules, which are not the same as other verbs. This post offers an overview (or review) of how modal verbs are different from other verbs, and how/why we use them in English.

To start off, here is a list of common modal verbs.

Modal verbs…
…most often to talk about the present.	can, must, may, shall, ought, might
… most often to talk about the past.	could + have, would + have, should + have, may + have, might + have
… most often to talk about the future.	may, might, will, could, should, would

Here are some ways that modal verbs are different from other English verbs.

Modal verbs always require another verb with them in the sentence; they cannot be the main verb of a sentence.

For Example:
I can speak English very well. I can English very well.
You should clean your room. You should your room.

Modal verbs are followed directly by the infinitive of another verb without ‘to’ in front of the infinitive.

For example:
We will dance together all night. We will to dance all night.
They might tell the secret. They might to tell the secret.

The modal verb is not conjugated and neither is the main verb it modifies – just use the infinitive version of the main verb.  Also, the main verb never takes “-s” in the third person present (this is a common mistake).

For example:
She can cook very well. She can cooks very well.
He would come over if he could. He would comes over if he could.

The word “not” is used to make the negative with modal verbs.

For example:
You should not be late to class. You should no be late for class.
Grandpa might not visit us this winter.  Grandpa might no visit us this summer.

Questions that involve modal verbs use inversion. When making a question with a modal verb, the modal verb should be at the start of the question, followed by the subject, and then the main verb.

For example:
Can she come over?
Will you call the police?

Now, here are some reasons why we use modal verbs in English.

They are used to express probability, certainty, or speculation.

For example:
It’s sunny outside, so it must be hot.
My bill can’t be right, I didn’t order all this food.

They are used to express ability or used to talk about skill (generally use ‘can’ or ‘could’ for this).

For example:
Sally can type faster than anyone in the class.
I couldn’t drive until a year ago when I got my license.

They are used to express obligation or necessity and to give advice (generally use ‘must’ and ‘should’ for this).


For example:

You should drive slower when you are near a school.
We must complete this assignment tonight.

They are used to ask for or give permission (generally use ‘can,’ ‘could,’ and ‘may’ for this).


For example:
Could I have your dessert, if you don’t want it?
He may not spend his vacation with us!

They are used to talk about habits (past, present, and future) or repeated past events (generally use ‘will’ or ‘would’ for this).

For example:
When I was a little girl, we would often play out in the yard until it was dark.
No matter what I do, we will always be late leaving the house in the morning.

I hope this overview of modal verbs has been helpful!