Definition

A modal is an auxiliary verb used with a main verb. Modals affect the main verb's meaning and tense.

Modals accompany verbs and add to their meaning

Types of Modals
Modals: Affirmative Form
Modals: Negative Form
Modals: Question Form

Types of Modals

Modals can be organized into types. These types indicate the meaning added to a verb.

Modals of Ability

Can is used to express:

present abilities and skills

Could is used to express:

past abilities and skills
conditional abilities and skills

Examples

Present ability: She can jump very high.

An old superhero remembers when he could lift a car.

Past ability: “When I was younger, I could lift a car with only one hand.”
Conditional ability: “Maybe I could still lift a car, if I trained very hard.”

Modals of Advice

Should is used to:

give advice
make a recommendation

Could is used to:

give advice
suggest a solution to a problem

Examples

A superhero crashed on the ground and another tells him to practice his landing.

“You should practice your superhero landings.”

A superhero has a very long cape and another one tells him it could be shorter.

“The cape could be shorter.”

Modals of Obligation

Must is used:

to express an obligation in the present

Have to is used:

to express an obligation
to express present, past and future tenses
with other modals

Examples

A monster is destroying a building and a superhero is ready to defend his city.

“I must defend my city!”

A superhero is badly hurt and another advises him to be more careful.

Present: “You have to be more careful.”
Past: “You had to land on your feet, not your face!”
Future: “You will have to take it easy for a few days.”

Be careful!

The modal have to is different:

it can be used in several verb tenses and change forms
it can be used with other modals

Other modals (can, could, should, etc.):

never change forms
always use a single modal with the main verb

Have to uses:		Examples:
Present	have to	We have to team up against that supervillain.
Present	has to	She has to practice her superhero landing.
Past	had to	They had to run away because their enemy was too strong.
Future	will have to	I will have to wash my costume after my fight with Skunk-Man.
Conditional	would have to	We would have to build a new secret base if you hadn’t defended it.
Possible Obligation	may have to	You may have to fight that bad guy again: he escaped last night.

For Advanced Users: Shall & Ought To

Modals of Possibility

May is used to express:

a good probability the action will happen or is true

Might is used to express:

a fair probability (not as probable as may)
a possibility in the past (past form of may)

Could is used to express:

a possibility the action will happen or is true

Examples

It may take a long time to learn to fly properly.

A man does a risky scientific experiment.

Present: He might accidentally get super powers.
Past: It might have worked, if there had not been any problems.

A superhero explains his plan to another.

“I think this plan could work.”

Modals of Request

Modals of request (also called modals of permission) are used in the interrogative form. They begin a question.

Can is used to:

ask permission with very familiar people
make a request with very familiar people
offer your help

→ Use it moderately.

May is used to:

ask permission in a formal situation or with someone you’re a little less familiar with (like your teacher!)

→ Use in most cases.

Could is used to:

make formal or informal requests
ask permission

Would is used to:

make formal requests

Example

A cat is stuck in a tree and a superhero asks a girl if he can help.

“Can I help you with your cat?”

A superhero has a utility belt in hand. Another seems angry and answers no.

“May I borrow your utility belt?”

A superhero asks another if he can hold a piano.

“Could you hold this for me?”

A man is attached to a chair and asks a superhero to save him.

“Would you please save me?”

Find out more!

Some modals only affect the tense but not the meaning of the verb.

Will indicates the future tense.
Example: They will fight the villain tomorrow.
Would may indicate conditional.
Example: If she knew how to fly, she would be the best.

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Modals: Affirmative Form

Points to remember when forming affirmative sentences with a modal:

The modal is an auxiliary verb that is placed before the main verb.
Use the base form of the main verb.

Structure of an affirmative sentence with a modal verb.

Examples

“I can grow new arms!”

“You must wear something else.”

“I should get a plane.”

Modals: Negative Form

Points to remember when forming negative sentences with a modal:

Place the modal (auxiliary verb) before the function word not.
Place the function word not between the modal and the verb.
Use the base form of the verb.

Structure of a negative sentence with a modal verb.

Contractions

Modals can be used in their long form or their contracted form.

Long form	Contracted form
could not	couldn't
should not	shouldn't
would not	wouldn't
cannot	can't
will not	won't
must not	mustn't*
might not	mightn't*
shall not	shan't*