The Modals in English Grammar The Modals A) Can and Could as ‘Possibility’ & ‘Ability’. The most important meaning of Can and Could is ‘to be able to’. He can walk thirty Miles a day. We can play tennis. She cannot play tennis. When she was young, she could swim across the lake. B) Can and Could as Permission: Ravindra can’t smoke here, but … [Read more...] about The Modals in English Grammar