What is the infinitive?

1. Form

The infinitive is the base form of a verb. It may be preceded by ‘to’ (the to-infinitive) or stand alone (the base or zero infinitive).

2. Infinitive with or without ‘to’

The to-infinitive is used:

  • after certain verbs. e.g. want, wish, agree, fail, mean, decide, learn
  • after the auxiliaries to be toto have to, and ought to
  • in the pattern ‘it is + adjective + to-infinitive’


with ‘to’

  • The elephant decided to marry the mouse
  • The mouse agreed to marry the elephant
  • You will have to ask her
  • You are to leave immediately
  • He ought to relax
  • She has to go to Berlin next week
  • It’s easy to speak English
  • It is hard to change jobs after twenty years
  • It’s stupid to believe everything you hear

without ‘to’

  • would rather visit Rome.
  • She would rather live in Italy.
  • Would you rather eat steak or fish?
  • He would rather work in a bank.
  • I’d rather be a forest than a tree.