Grammar: Modal Verbs (Can, Must, Should) – English – 2nd Year Middle School – Algeria

Modal Verbs: Can, Must, Should

Modal verbs are auxiliary verbs that express ability, obligation, permission, or advice. They are used before the base form of the main verb.

CAN – Ability and Permission

• Ability: “I can speak English.” / “She can swim very well.”
• Permission: “Can I go to the bathroom?” / “You can use my pen.”
• Negative: cannot / can’t: “I can’t play the guitar.”

MUST – Obligation and Necessity

• Obligation: “You must do your homework.” / “Students must obey the rules.”
• Negative: must not / mustn’t (prohibition): “You mustn’t smoke here.”

SHOULD – Advice and Recommendation

• Advice: “You should study hard.” / “We should eat healthy food.”
• Negative: shouldn’t: “You shouldn’t eat too much sugar.”

Rules for Modal Verbs

• No -s in third person: “He can swim” (NOT “He cans swim”)
• Followed by base verb: “You must go” (NOT “You must to go”)
• Questions: invert subject and modal: “Can you help me?” / “Should I wait?”

Exercises

1. Complete with can/must/should: “You ___ respect your parents – I ___ speak French – You ___ study more”.
2. Make negative: “You can enter – You must go – You should eat this”.
3. Make questions: “I can go – He must leave – We should help”.

See also Grammar: Modal Verbs (Can, Could, May, Might) and Grammar: Imperatives and Suggestions.