The infinitive is the basic form of the verb and it can have three possible endings: -ar (cantar [to sing]), -er (comer [to eat]), or -ir (vivir [to live]). In Spanish, the infinitive can function as a verb or a noun. It is used after certain verbs, adjectives and some expressions.
The infinitive can refer to the subject, to the object, or to an impersonal construction.
Infinitive without preposition
after ser + indefinite article/possessive pronoun + noun: Es un placer ayudar si alguien necesita consejo (It’s a pleasure for me to help if someone needs advice).
es una alegría (it’s a pleasure/joy)
es mi deber (it’s my duty)
es un placer (it’s a pleasure)
es mi obligación (it’s my duty/obligation)
es una vergüenza (it’s a pity/shame)
after the following modal verbs: Debes empezar en el nivel de iniciación (You must begin in the initial level).
deber (must/should/ought)
poder (can/to be able/to be allowed)
saber (to know/to be able)
soler (to usually/generally/normally do something)
after impersonal expressions with ser + adjective: No es fácil jugar así, pero es increíble (It’s not easy to play like this, but it’s amazing).
es difícil (it’s difficult)
es importante (it’s important)
es (im)posible (it’s (im)possible)
es (in)necesario (it’s (un)necessary)
es inútil (it’s useless/pointless)
es menester (it’s necessary)
es peligroso (it’s dangerous)
es preciso (it’s necessary/required)
after verbs that usually take a direct object: Quiero comprar una buena raqueta (I want to buy a good racket).
desear (to desire/to wish)
evitar (to avoid/to evade)
intentar (to try/to attempt)
pensar (to think to/to plan to)
pretender (to claim/to pretend)
proponerse (to decide/to plan to do something)
Infinitive with preposition
The infinitive is also used after certain verbs with the prepositions a, con, de, en, para, and por.
verb + a + infinitive: Empezaré a jugar al tenis, aunque no estoy acostumbrado a hacer mucho deporte (I’ll start to play tennis, even though I’m not used to doing a lot of sport).
acostumbrarse a (to be used to)
ayudar a (to help someone)
comenzar a (to begin/to start to)
decidirse a (to decide to)
empezar a (to begin/to start to)
estar + adjective + a (to be + adjective + preposition)
incitar a (to encourage/to incite to)
obligar a (to obligate/to force someone to)
persuadir a alguien de (to convince someone to)
renunciar a (to renounce/to give up)
verb/expression + en + infinitive: Tengo interés/Estoy interesado en apuntar también a mi hijo a las clases (I’m interested in signing my son for the courses).
complacerse en (to take pleasure in)
detenerse en (to delay oneself with)
empeñarse en (to strive to/to struggle for)
entretenerse en (to pass the time with/to entertain oneself with)
estar + adjective + en (to be at something)
insisitir en (to insist on)
ocuparse en (to occupy oneself with)
pensar en (to think of/about)
ser + adjective + en (to be + adjective + at something)
tardar en (to hesitate/to delay in)
tener gusto en (to gladly do something)
tener interés en (to have interest/be interested in)
ser el primero/último en (to be the first/last to)
verb + de + infinitive: Él nunca ha dejado de entrenar diariamente (He has never stopped training daily).
alegrarse de (to be happy about/glad of)
arrepentirse de (to regret)
avergonzarse de (to be ashamed of)
cansarse de (to be tired of)
dejar de (to stop/to cease)
encargarse de (to handle/to take care of)
parar de (to stop/to cease)
tratar de (to try/to attempt)
verb + adjective/noun/… + de + infinitive: Estoy deseoso de empezar con las clases (I’m eager to start school)
hacer a alguien el favor de (to do someone the favor of)
correr peligro de (to be at risk of)
estar a punto de (to be about to)
estar + adjective + de (to be + adjective + to)
no hay manera de (it’s impossible/there’s no way to)
ser + adjective + de (to be + adjective + to)
tener la costumbre de (to have the habit of)
tener el derecho de (to have the right to)
tener el deseo de (to have the desire to)
tener ganas de (to have the inclination/desire to)
tener la intención de (to intend/to have the intention to)
verb/expression + para + infinitive: No tengo tiempo para entrenar (I don’t have time to train).
arreglárselas para (to manage to)
autorizar a alguien para (to authorize someone to)
servir para (to be used for/to serve to)
(no) tener motivo para (to have (no) reason)
(no) tener tiempo para (to have (no) time)
tener permiso para (to have permission to/to be allowed to)
verb + por + infinitive: Me esfuerzo por ser el mejor (I make an effort to be better).
esforzarse por (to make an effort)
estar + adjective + por (to be + adjective + for)
luchar por (to fight for)
felicitar a alguien por (to congratulate someone on)
verb + con + infinitive: Sueño con ser un jugador profesional (I dream of being a professional player).
amenazar con (to threaten someone with)
bastar con (one only needs/… suffices)
Shortened dependent clauses
The following prepositions and prepositional phrases + infinitive can be used to help shorten dependent clauses when the subject in the main clause and the dependent clause is the same.
final preposition + infinitive: Tenemos que entrenar duro a fin de ser los mejores (We have to train hard in order to be the best).
con ánimo de (with the aim/intention of)
con el fin de (with the purpose of)
con (el) objeto de (in order to/with the intention of)
consecutive preposition + infinitive: Ha entrenado hasta el punto de no tener tiempo libre (He has trained so long that he has no free time).
a/hasta tal punto de (so long that/to the point that)
al extremo de (so far that)
conditional preposition + infinitive: Entrenaré contigo a condición de jugar diariamente (I’ll train with you on the condition that we play daily).
a condición de (on the condition that)
causal preposition + infinitive: No estudió lo suficiente con el pretexto de entrenar más horas (He didn’t study enough on the pretext that he had to train more hours).
con el pretexto de (on the pretext of/that)
concessive preposition + infinitive: A pesar de entrenar muchas horas no gané (Although I trained many hours, I didn’t win).
modal and other prepositions + infinitive: A fuerza de mucho entrenar gané (I won by training a lot).
además de (rather, besides/plus/in addition to)
a fuerza de (by, by way of)
temporal preposition + infinitive. In this case we also have to change the introductory section of the relative clause: Hablaré con el profesor antes de que empiece el entrenamiento → Hablaré con el profesor antes de entrenar (I will talk to the teacher before training starts).
hasta que -> hasta (until)
antes de que -> antes de (before)
después de que -> después de (after)
