Four Uses of the Infinitive with To
The infinitive with to (to + base verb) appears in four main situations in English.
a. To express purpose (why someone does something)
b. After certain verbs + direct object (advise, tell, warn, persuade, etc.)
c. After certain verbs (agree, like, prefer, want, etc.)
d. After certain adjectives (easy, happy, hard, ready, etc.)
a. To Express Purpose
Use the infinitive with to to explain why someone does something. It answers the question "What for?"
She went to the library to study. (Why? To study.)
He called me to ask for help.
I save money to travel every summer.
b. Verb + Direct Object + Infinitive
Some verbs are followed by a direct object (a person) and then the infinitive. Common verbs: advise, tell, warn, persuade, ask, encourage, invite, remind, teach.
She told me to be quiet. (told + me + to be)
He warned us not to touch it.
They persuaded her to stay.
My teacher encouraged me to apply for the scholarship.
c. Verb + Infinitive
Some verbs are directly followed by the infinitive with no object in between. Common verbs: agree, want, prefer, decide, hope, need, plan, refuse, seem, offer, learn, forget, manage.
I want to see that film.
She agreed to help us move.
He refused to answer the question.
They decided to leave early.
d. Adjective + Infinitive
Some adjectives are followed by the infinitive with to. Common adjectives: easy, hard, difficult, happy, glad, ready, surprised, important, possible, impossible.
It is easy to understand.
She was happy to hear the news.
Many of us find it hard to communicate.
Are you ready to start?
⚠ Common mistakes:
✗ She told me be quiet. → ✓ She told me to be quiet. (verb + object needs to)
✗ He went to the shop for buy bread. → ✓ He went to the shop to buy bread. (purpose = infinitive, not for + verb)
✗ I want go home. → ✓ I want to go home. (want + infinitive)