Infinitives are the "to" form of verbs

hablar ~ to talk
bailar ~ to dance
comer ~ to eat
vivir ~ to live

ALL verbs have an infinitive form.

We change the infinitive depending on who is doing the action

If "yo" (I) is doing the action.... the verbs in end -o-

Yo hablo
Yo bailo
Yo como
Yo vivo

If we are talking about 1 other person... the endings will be either - a- or -e-.

Mi madre habla ~ because the infinitive is an -ar verb (hablar).
Mi papá baila ~ because the infinitive is an -ar verb (bailar).
Mi hermano come ~ because the infinitive is an -er verb (comer).
Mi abuelo vive ~ because the infinitive is an -ir verb (vivir).

Let's PRACTICE!