MODALS

[] (can/can’t/could/couldn’t) [] (have to/don’t have to) [] (should)

http://www.ego4u.com/en/cram-up/grammar/modal-verbs/exercises?02 (vari) http://www.ego4u.com/en/read-on/animals/soccer/exercises (mustn't - needn't) [] (vari) [] (vari) [] (present, past, future) [] (present, past, future) [] (needn’t have) [] (vari) [] (modali composti)