Verbs have many different forms. First, there are finite and non-finite verb forms. English sees , for example, has the ending - s to agree with the subject he, she or it , and it is present tense as opposed to past tense saw . Non-finite verb forms do not have endings which agree with the subject and do not change for tense. All other verb forms are finite.
Finite verbs have endings which agree with the subject of the verb for person and number .
3rd person 3rd pers. Voice indicates the perspective of an event which is being adopted by the speaker. Tenses give some indication of time. Some languages have further subdivisions within each of these categories. The indicative mood is the most general mood.