modal verbs

1. MODAL VERBS
 MAIN FEATURES
MODAL VERBS
MODAL PERFECT

2. MAIN FEATURES
 They are followed directly by the infinitive of another verb (without
TO)
 They don’t use an ‘s’ for the third person singular or ‘ed’ for the
past
 They are never used with other auxiliary verbs. QUESTIONS are
formed by inversion. NEGATIVE is formed adding NOT to the verb

3.  TO TALK ABOUT ABILITY:
MODAL VERBS
CAN/CAN’T
COULD/COULDN’T
BE ABLE TO/ NOT BE ABLE TO
 TO EXPRESS OBLIGATION:HAVE TO/ DON’T HAVE TO
NEED TO/ NEEDN’T
MUST (not MUSTN’T)
 TO EXPRESS PROHIBITION: MUSTN’T
CAN’T
 TO EXPRESS CERTAINTYMUST
 TO EXPRESS POSSIBILITY
MAY/ MAY NOT
MIGHT/ MIGHT NOT
COULD/ COULDN’T
 TO GIVE ADVICE
TO MAKE
SHOULD/
SHOULDN’T
OUGHT TO

4. MODAL PERFECT
 TO EXPRESS AN ALTERNATIVE PAST ACTION:
CAN’T HAVE + PARTICIPLE
 TO EXPRESS A CERTAINTY IN THE PAST:MUST HAVE + PARTICIPLE
 TO EXPRESS A POSSIBILITY IN THE PAST:MAY/ MIGHT HAVE + PARTICIPLE
TO EXPRESS A IMPOSSIBILITY IN THE PAST:
COULD HAVE + PARTICIPLE
TO SUGGEST A CRITICISM FOR A PAST ACTION:SHOULD HAVE + PARTICIPLE