In English, verbs are conjugated (or changed) to match the pronoun. This involves changing the termination (ending) of the verb. This change is not as great as some other languages like Spanish or French. Verbs can be conjugated for time as well.
In English there are verb which are conjugated regularly (following a normal pattern) and irregular verbs which do not. For example, in the simple present tense all conjugations for regular verbs are the same. The only conjugation that is different is he/she/it which ends in "s" (i.e. He eats).
An example of an IRREGULAR verb is "be":