The Infinitive The infinitive is the base of the form of the verb. Gramatically there are two types of infitives: The full infinitive: when to is used before the verb. The bare infinitive: when there is no to.
The full infinitive is used: After certain verbs. Ex: We prefer to go to the beach. After impersonal phrases (it+be+adjective). Ex: It is nice to meet you. After verbs that follow the construction verb+someone+ to do something. Ex: My mother allowed me to go to the cinema.
After the verbs when we use them in pasive. Ex: He was forced to stay at home. After be in a formal instruction or information about the future. Ex: You are to be quiet until he finishes talking. To express purpose. Ex: i’m studying to get my driving licence.
The bare infinitive is used: After verbs which follow the construction verb+someone+do something. Ex: The teacher let us study for the exam. After modal auxiliary verbs (some modals contain to in themselves). Ex: We shouldn’t move from here.