Many English verbs, when followed by another verb, require the to-infinitive — the form to + base verb (to go, to leave, to know). This is one of the most common verb patterns in the language.
The pattern is simple to build. The real work is knowing which verbs take it — and English has several dozen. Grouping them by meaning makes them far easier to remember than a single alphabetical list.
Verbs of wanting and planning
These verbs describe intentions, goals, and decisions about the future. They are by far the most frequent group.
want, hope, plan, intend, expect, wish, decide, choose, aim
Verbs of agreement and refusal
These verbs describe a spoken or social commitment — or the refusal of one.
agree, refuse, promise, offer, consent, volunteer
Verbs of effort and attempt
These describe trying, succeeding, or failing at an action.
try, manage, attempt, fail, struggle, afford, learn
Verbs of appearance and tendency
These describe how something looks or what usually happens. They are often followed by to be + adjective.
seem, appear, happen, tend
Verbs of starting and continuing
begin, start, continue describe the phases of an action. They take the to-infinitive naturally.
These three verbs can also take the -ing form with almost no change in meaning (It started raining). That choice is covered separately.
Verb + object + infinitive
A large group of verbs takes a different pattern: verb + object + to-infinitive. Here the infinitive describes what the object does, not what the subject does.
tell, ask, invite, advise, allow, remind, warn, want, expect, encourage, order, teach
Some verbs fit both patterns depending on meaning. Compare:
The object is usually a person or pronoun, and the object pronoun form is required: me, him, her, us, them — never I, he, she, we, they.
The negative form
To make the infinitive negative, put not directly before to. Never split to and the verb.
Placing not after to (to not go) is occasionally heard in informal speech, but it reads as awkward and should be avoided in standard writing.
Common mistakes
Using -ing instead of the infinitive
Forgetting "to"
Wrong negation placement
Object form in verb + object + infinitive
Missing object where required