Grammar Rules · Modal verbs: can, could, must, have to
Modal verbs: can, could, must, have to.
A modal verb takes the base verb, with no "to" and no -s: "She can swim", never "can to swim" or "cans swim". "Must" has no past form; for past obligation use "had to". "Don't have to" means something is not necessary.
Wrong → right
| Common mistake | Corrected |
|---|---|
| I can to swim. | I can swim. |
| She cans speak French. | She can speak French. |
| He must to finish the report today. | He must finish the report today. |
| We must worked late yesterday. | We had to work late yesterday. |
| You don't must pay for the update. | You don't have to pay for the update. |
| He can plays the guitar. | He can play the guitar. |
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