The endings for regular IR verbs are:

O
ES
E

IMOS
ÍS
EN


A regular IR verb conjugated correctly should look similar to this:
Vivo
Vives
Vive

vivimos
vivís
viven

In the exercise that follows, conjugate the verb according to the subject. Hint: If you are having trouble finding the subject, look for a subject pronoun (yo, tú, etc.) and remember that for statements, Spanish syntax usually places the subject right in front of the verb. If you do not know the vocabulary, please consult a good dictionary.