Complex object is formed by a combination of noun or pronoun and an Infinitive or Gerund.
My teacher wants me to do my homework.
Infinitive complex object that follows verbs hear, see, watch, feel, let, make is used without "to".
I saw him cross the street.
The infinitive form of a verb is usually preceded by "to" (e.g., to run, to dance, to think). Example: I don't like to run.