Modal Verbs (modal auxiliaries)
Modal auxiliary verbs may sound difficult but in fact they're easy. They are invariable (no conjugation). And the main verb is always the "bare infinitive" (the infinitive without "to").
Can, Could, Be able to
Have to, Must, Must not/Mustn't
Shall versus Will
Modal auxiliary verbs may sound difficult but in fact they're easy. They are invariable (no conjugation). And the main verb is always the "bare infinitive" (the infinitive without "to").
Can, Could, Be able to
Have to, Must, Must not/Mustn't
Shall versus Will