Modal Verbs
Can, must, should, could and more — the small verbs that add big meaning: ability, permission, obligation, advice and possibility.
Press a button. Change the meaning.
Modal verbs add meaning — ability, obligation, advice. Swap the modal and the form, and watch the same sentence change what it means.
Got the idea? Jump to the practice →
The rules — with examples
The most common modals and their meanings, the form, and the negatives.
Three you’ll use every day
Can I go?
I must go now.
Should I call?
Watch out: a modal is always followed by the base verb — no to, no -s, no -ed: “She can swim”, never “can to swim” or “cans swim”.
Which modal for which meaning
Negatives
More modals & a trap
Possibility & a reminder: use might, may or could for things that are perhaps true (“It might rain” = maybe it will). And modals never change for he/she/it — “He can”, never “He cans”.
Practise & score yourself
Ten quick questions with instant scoring and a short explanation for every answer — especially the ones you get wrong.
The one rule to remember
Modal verbs (can, must, should, could, might…) add meaning to a sentence — ability, permission, obligation, advice or possibility. They are always followed by the base verb and never change for he/she/it: “She can swim”, “He must go”.