Modal verbs express ability, possibility, obligation, permission or advice. 🔹 Ability : • can / could : She can speak three languages. He could swim when he was five. • be able to : I have never been able to understand this. 🔹 Possibility : • may / might : It may rain later. She might not come. (50% or less certain) • could : That could be the answer. 🔹 Obligation and necessity : • must : You must wear a seatbelt. (strong obligation, speaker's view) • have to : I have to be home by 10pm. (external rule) • need to : You need to revise more carefully. 🔹 Prohibition : • must not (mustn't) : You mustn't cheat in exams. • cannot (can't) : You can't park here. 🔹 Absence of obligation : • don't have to / needn't : You don't have to come if you're tired. 🔹 Advice : • should / ought to : You should get more sleep. You ought to apologise. 🔹 Modals in the past : • could have + PP : She could have passed if she had studied. • should have + PP : I should have called you. (regret) • must have + PP : He must have left already. (deduction)

📝 Choose the correct modal : 1. You _______ smoke in hospital — it's forbidden. → mustn't 2. She _______ speak Arabic — she learnt it as a child. → can 3. You _______ wear a uniform at this school — it's the rule. → have to 4. He _______ be at home — his light is on. → must 5. You _______ study more — your results are dropping. → should 6. I _______ come if you don't want me to — it's up to you. → don't have to 📝 Past modals — express regret or deduction : 1. 'He failed.' — 'He _______ (study) more.' → should have studied 2. 'She isn't here.' — 'She _______ (leave) already.' → must have left 3. 'I was free.' — 'You _______ (come) to the party!' → could have come