Infinitives

Overview
Uses

Overview

The infinitive is the uninflected form of the verb such as to read, to write, to count, etc. Infinitives are divided into three categories: -ar, er, and -ir verbs. In addition to being the source of conjugated verbs, they also serve specific functions as parts of speech in their own right. They can be used in a causative construction, after verbs of sensory perception, after prepositions, as nouns, and as verbal objects.

Uses

Causative constructions

If a speaker does not actually perform an action, but instead causes something to happen, a causative construction can result. Verbs such as mandar, hacer, and dejar typically form part of the utterance.

Me mandaron sacar fotos. (They ordered to me to take photos.)
Les hicimos cantar para todos. (We made them sing for everyone.)
Le dejé salir sin pedir permiso. (I let him leave without asking permission.)

Senses

Infinitives can follow verbs that imply a sensory perception, such as sentir, percibir, ver, oír, oler, etc.

Sentí pasar el espíritu. (I sensed the spirit pass by.)
Vimos despegar el avión. (We saw the airplane take off.)

Following prepositions

After prepositions such as después de, antes de, para, sin, etc. the infinitive follows, despite the -ing ending in English.

Comenzamos después de llegar. (We began after arriving.)
Ganamos sin saberlo. (We won without knowing it.)

The infinitive as a noun

The infinitive can be used as a noun, and it can function as a subject or as an object. As in the previous use, care should be taken not to allow the distraction of English usage, i.e. an -ing ending.

El pasarse de la raya no es una buena idea. (Going overboard is not a good idea.)
Se oía el chirriar de la puerta. (One could hear the door squeak.)

Verbal object

Mirroring English syntax, many verbs precede the infinitive, which acts as an object of the verb.

Debemos ahorrar más. (We should save more.)
Sé conducir. (I know how to drive.)
Necesito cambiar mi llanta desinflada. (I need to change my flat tire.)