MODAL VERBS

EXPRESSING ABILITY
CAN - CAN'T - BE ABLE TO - MANAGE TO

(1)

(2)

(3)

EXPRESSING OBLIGATION

MUST-DON'T HAVE TO; HAVE TO; MUSTN'T

EXPRESSING PROBABILITY 

(MUST-CAN'T; MAY-MIGHT)

GIVING ADVICE
(SHOULD - OUGHT TO - HAD BETTER)

GIVING ADVICE / OPINION
EXPRESSING PROBABILITY / EXPECTATION / OBLIGATION OR DUTY
(SHOULD - SHOULDN'T)