Modal Verbs

Modal verbs are special helping words. They come before action words to tell us what we can do, what we must do, or what we may do.

What You'll Learn

How to use can, cannot, may, must, and should
How to pick the right modal verb for each sentence

When to Use

Saying what you are able to do: "I can swim."
Asking if you are allowed: "May I go out to play?"
Saying what you have to do: "You must brush your teeth."

How to Form

A modal verb comes before the action word. The action word stays in its base form -- do not add -s or -ed.

Modal	What it means	Example
can	I am able to	"I can read this book."
cannot	I am not able to	"He cannot reach the top."
may	I am allowed to	"You may sit down."
must	I have to	"We must be quiet."
should	It is a good idea	"You should eat your vegetables."

Key Rules

Do not add -s to the action word: Say "She can run." Do not say "She can runs."
Do not put "to" after the modal: Say "I must go." Do not say "I must to go."
"Cannot" is one word: Write "I cannot fly." Do not write "I can not fly."

Common Mistakes

Wrong	Right	Why
She can swims.	She can swim.	Do not add -s after a modal verb
I must to sleep.	I must sleep.	Do not put "to" after a modal verb
I can not ride a bike.	I cannot ride a bike.	"Cannot" is written as one word

Clue Words

Ability (can / cannot)

able to, know how to

Permission (may)

allowed, let me, please

Must do (must / should)

have to, need to, it is important

Tip: Ask yourself: "Am I able to do it?" Use can. "Am I allowed?" Use may. "Do I have to?" Use must. "Is it a good idea?" Use should.

Practice Tips

Try each modal: Read the sentence and try putting each modal verb in the blank. Pick the one that makes the most sense.
Check the action word: After a modal verb, the action word should have no -s and no "to" before it.

Quick Reference

I want to say...	Modal	Example
I am able to	can	I can hop on one leg.
I am not able to	cannot	She cannot open the jar.
Am I allowed?	may	May I have a drink?
I have to do this	must	You must listen to Mummy.
It is a good idea	should	You should say thank you.

Modal Verbs (P1) (Primary 1)