Infinitive with "to"

We use the infinitive with “to” (to do) in the following situations:

1. After some verbs

After certain verbs, such as want, need, would like, decide, hope, learn, offer, plan, pretend, promise, and try, we use the infinitive with “to” if another verb follows.

2. After adjectives

When we use a verb after an adjective, we usually use the infinitive with “to”.

3. After question words

We can use the infinitive with “to” after question words such as what, who, where, when, and how.

4. To explain why we do something

We can use the infinitive with “to” to explain the purpose or reason for doing something.

The negative form of "to do" is "not to do".