1. MODAL VERBS CHARACTERISTICS They are auxiliary verbs. To form the negative we add not. They have the same form for all the persons. They are followed by the infinitive without to. have to is a semi modal.

2. OBLIGATION Must Have to (has to) LACK OF OBLIGATION Don’t/ doesn’t have to Needn’t Don’t need to

3. ADVICE Ought to Should Shouldn’t Must PROHIBITION Can’t Mustn’t

4. OBLIGATION AND ADVICE IN THE PAST PresentPast Must/ have toHad to Needn’tNeedn’t have + past participle Don’t/ doesn’t need toDidn’t need to Don’t/ doesn’t have toDidn’t have to ShouldShould have + past participle OughtOught to have + past participle

5. ABILITY AND PERMISSION Can’t/ can’t: –to express ability in the present. –To give permission Could/ couldn’t: –to express ability in the past. –To express permission in the past. Be able to: –To express ability in different tenses –In the past tense: manage Can/ could/ may –To ask permission.

6. SPECULATION AND DEDUCTION 100% Certainty MUST 0% Certainty CAN’T Probability Could Might May

7. SPECULATION AND DEDUCTION IN THE PAST PRESENTPAST MayMay have + past participle MightMight have + past participle CouldCould have + past participle Can’tCan’t have + past participle MustMust have + past participle