The infinitive (el infinitivo ) is the most basic form of a Spanish verb. Verbs in the infinitive form are not conjugated and do not indicate anything about who is performing an action or at what point in time the action is taking place.
In English, infinitive verbs are preceded by the word to, as in to speak, to read, or to write.
In Spanish, infinitives are only one word and end in either -ar, -er, or -ir, as in hablar , leer , and escribir .
Verb Stems
Many verb tenses use a form of the infinitive as the stem to which verb conjugation endings are attached. In general, for regular verbs, you simply need to remove the infinitive ending (-ar, -er, or -ir) to find the stem, and then you can the add specific endings needed to give tense/subject information.
-ar Verbs
Verbs that end in-ar are more common than -er and -ir verbs. There are also fewer irregular -ar verbs than -er or -ir verbs. Here are some examples of common -ar infinitives and their stems.
Infinitive Definition Stem
buscar
to look for busc-
cantar
to sing cant-
comprar
to buy compr-
escuchar
to listen to escuch-
extrañar
to miss/to yearn for extrañ-
hablar
to speak habl-
llamar
to call llam-
llenar
to fill llen-
llevar
to carry llev-
mirar
to watch mir-
visitar
to visit visit-
-er Verbs
Verbs that end in -er are the second-largest group of infinitives in Spanish. Here are some examples of common -er infinitives and their stems.
Infinitive Definition Stem
beber
to drink beb-
comer
to eat com-
comprender
to understand comprend-
correr
to run corr-
creer
to believe cre-
deber
to owe deb-
leer
to read le-
meter
to put into met-
romper
to break romp-
vender
to sell vend-
-ir Verbs
Verbs that end in -ir are the smallest group of Spanish infinitives. Here are some examples of common -ir infinitives and their stems.
Infinitive Definition Stem
abrir
to open abr-
asistir
to attend asist-
cubrir
to cover cubr-
escribir
to write escrib-
incluir
to include inclu-
pedir
to order ped-
permitir
to allow permit-
recibir
to receive recib-
servir
to serve serv-
vivir
to live viv-
