If a verb is followed by another verb, it must take a form of infinitive (to+verb) or gerund (verb+ing). Here are some examples:
infinitive: agree, choose, decide, hope, learn, plan, promise, wait, want, wish
gerund: admit, appreciate, enjoy, finish, give up, miss, tolerate, understand
both: begin/start, like, love, hate
both, but with a change in meaning: quit, stop, regret, remember
example: She stopped to pick a flower. (She stopped walking to do it.)
She stopped smoking. (She doesn’t smoke anymore.)