Spanish infinitives are the most basic form of a verb, representing the action in its purest, unconjugated state. They always end in one of three suffixes: -ar, -er, or -ir. Infinitives can function as nouns, appear after other verbs, form compound tenses, and convey general ideas of "to do something."

Usage

Spanish infinitives can be used in a variety of contexts:

As nouns: Express general ideas (e.g., "Fumar es malo" = "Smoking is bad").
After conjugated verbs: Complete the meaning (e.g., "Quiero comer" = "I want to eat").
Imperative with pronouns: Give commands without changing the verb (e.g., "Antes de salir, llama" = "Before leaving, call").
Fixed expressions: Appear in phrases like "Por favor, no fumar" (Please, no smoking).
Compound verb forms: Combine with other verbs (e.g., "Voy a estudiar" = "I’m going to study").

In which context do Spanish infinitives appear?

After conjugated verbs to complete meaning

Only as imperative commands

In fixed expressions and compound forms

As nouns expressing general ideas

Only in past tense constructions

Only in questions

As nouns expressing general ideas
After conjugated verbs to complete meaning
In fixed expressions and compound forms

Spanish infinitives can be used as nouns, after verbs, in fixed phrases, and in compound forms, among other contexts.

Structure

Spanish infinitives always end in one of three suffixes, which determines their conjugation group:

Ending	Example	English Meaning
-ar	hablar*	to speak
-er	comer*	to eat
-ir	vivir*	to live

The root is the part before the ending (e.g., com- in comer).

Examples

Infinitive	English Meaning	Example Sentence	English Example
hablar	to speak	Quiero hablar contigo.	I want to speak with you.
comer	to eat	Vamos a comer pizza.	Let’s eat pizza.
vivir	to live	Vivir* es aprender.	To live is to learn.
escribir	to write	Necesito escribir una carta.	I need to write a letter.
estudiar	to study	Voy a estudiar hoy.	I'm going to study today.

Quick Tips

Infinitives always begin with to in English (to speak, to eat, to live).
They do not change form for subject, number, or tense.
The infinitive is the form listed in the dictionary.
Use a + infinitive to say "to [verb]" (e.g., "Voy a salir").
Some verbs require a specific preposition before an infinitive (e.g., antes de comer).

Spanish infinitives are the building blocks for all verb forms and a key part of grammar.

Do Spanish infinitives change form based on subject or tense?

They change when used as nouns.

No, they remain unchanged regardless of subject or tense.

Yes, they change for singular and plural.

They only change in the past tense.

No, they remain unchanged regardless of subject or tense.

Infinitives are the base form and do not change for person, number, or tense.

Flashcards (1 of 8)

Ending: -ar
Example: hablar

English Meaning: to speak

Last updated: Wed Jun 18, 2025

Spanish