Question

complete the following statement about the negative form of the modals
for negative sentences with the modal verbs can,may and could, we use cannot or (A), may not and (B).​

Answer 1

a - can't

b - couldn't

may not não tem formalmente uma contração

existe "mayn't" mas realmente nunca nem vejo ninguém usar e nem aconselharia.

mas can + not vira can't contraído, e could + not vira couldn't