ABILITY IN THE PRESENT: CAN/CAN'T : Exercise 1
OBLIGATION/PROHIBITION: MUST/MUSTN'T : Exercise 1, exercise 2, exercise 3
ADVICE: SHOULD/SHOULDN'T: Exercise 1 exercise 2 exercise 3
PERMISSION AND OBLIGATION: CAN/HAVE TO : Exercise 1
PERMISSION, OBLIGATION AND PROHIBITION: MUST/ MUSTN'T/ CAN/ HAVE TO: Exercise 1
