Infinitives are the basic form in which verbs occur and can be found in both Spanish and English.
The Spanish infinitive is always a single word, whereas in English the infinitive is composed of two words always beginning with “to” (to sleep, to swim, etc).
When we consider Spanish infinitives, this is the form of the verb which is not conjugated. It’s the base form of a verb before we get into any form of conjugation, while it’s also sometimes used directly in certain sentence constructions.
In this post we’ll cover how to identify infinitives, and then get into their common uses in Spanish grammar.
Recognizing Infinitives
Spanish infinitive verbs come in three main forms, these correspond to the three verb types endings: -ar, -er, and -ir verbs.
In this section we’ll introduce you to these three main Spanish verb groups so you can start recognizing the infinitives, providing a list of examples of each type. For an introduction to Spanish verb conjugation we recommend checking out our dedicated post.
Spanish -ar verbs
This is the most common verb form, so you’re bound to come across -ar verbs all the time.
A prime example is the verb “to talk / to speak”: hablar. The verb stem is “habl-”, while the infinitive ending is “-ar”. To demonstrate this breakdown of the Spanish infinitive form of “hablar”, let’s take a look at its conjugation in simple present tense. Note that the stem “habl-” is the base of all the conjugations.
| Grammatical person | “Hablar” conjugation |
| 1st person singular | yo hablo |
| 2nd person singular | tú hablas / usted habla |
| 3rd person singular | él / ella habla |
| 1st person plural | nosotros / nosotras hablamos |
| 2nd person plural | ustedes hablan – vosotros / vosotras habláis |
| 3rd person plural | ellos / ellas hablan |
Here are a few other -ar verbs so you can start recognizing this common Spanish infinitive:
| Infinitive, Spanish | Infinitive, English |
| amar | to love |
| llegar | to arrive, to happen |
| comprar | to buy |
| buscar | to look for |
| bailar | to dance |
Spanish -er verbs
This is another common Spanish infinitive verb form, where the verb stem is followed by -er. A classic example is the verb “to eat”: comer. The verb stem is “com-”, with -er as the ending of its infinitive. Take a look at the simple present conjugation of “comer” and note how we base each form on the stem “com-”.
| Grammatical person | Comer conjugation |
| 1st person singular | yo como |
| 2nd person singular | tú comes / usted come |
| 3rd person singular | él / ella come |
| 1st person plural | nosotros / nosotras comemos |
| 2nd person plural | ustedes comen – vosotros / vosotras coméis |
| 3rd person plural | ellos / ellas comen |
Here are the Spanish infinitive forms of a few other common -er verbs:
| Infinitive, Spanish | Infinitive, English |
|---|---|
| correr | to run |
| vender | to sell |
| responder | to respond |
| beber | to drink |
| leer | to read |
Spanish -ir verbs
The third common infinitive form in Spanish consists of -ir verbs. The conjugation of -ir regular verbs uses the same vowel as -er verbs, that means: “e”. However, it has one difference (related to the conjugation for the 3rd person plural “nosotros”), though for recognizing infinitives they’re just as easy.
A good example of an -ir verb is “to live”: vivir. The stem is viv-, and its ending is -ir. We can see this in our vivir conjugation table like we saw with -ar and -er verbs, though note that the 1st person plural has the vowel “i” at the ending.
| Grammatical person | Vivir conjugation |
| 1st person singular | yo vivo |
| 2nd person singular | tú vives / usted vive |
| 3rd person singular | él / ella vive |
| 1st person plural | nosotros / nosotras vivimos |
| 2nd person plural | ustedes viven – vosotros / vosotras vivís |
| 3rd person plural | ellos / ellas viven |
Here are a few other common Spanish -ir verbs in infinitive:
| Infinitive, Spanish | Infinitive, English |
| existir | to exist |
| recibir | to receive |
| abrir | to open |
| escribir | to write |
| subir | to go up |
Irregular Infinitives
So far, all the infinitives we’ve seen in the three regular categories were pretty straightforward. Their -ar, -er, and -ir endings clearly help us to identify them as infinitives, while also defining how we’ll approach their conjugation.
Even where verbs with these three common endings to their infinitives have irregular conjugations, we can therefore still generally recognize their infinitives without needing to learn the specifics of the irregular conjugations.
Some Spanish verbs are very irregular, however, with infinitive forms that aren’t as easy to recognize. As a beginner learning Spanish, you’ll need to just memorize these irregular Spanish infinitives as you start studying conjugation.
Note that although these irregular infinitives generally also end with -ar, -er, or -ir like their regular counterparts, they can’t be separated into stem and ending like we saw with the regular infinitives, and sometimes they’re not even pronounced the same way. Let’s see a few of the most common irregular Spanish infinitives, along with their present indicative conjugations to demonstrate this difference:
Ir – to go: At a glance it might seem as though you’re looking at an -ir verb. But nothing could be further from the truth as we can see from its conjugation:
| Infinitive | ir |
| 1st person singular | yo voy |
| 2nd person singular | tú vas / usted va |
| 3rd person singular | él / ella va |
| 1st person plural | nosotros / nosotras vamos |
| 2nd person plural | ustedes van – vosotros / vosotras váis |
| 3rd person plural | ellos / ellas van |
Ser – to be: Another example of deceiving appearances, this infinitive has some resemblance to an -er verb. We can’t break it down into stem and ending, however. Ser is one of the most important irregular verbs in Spanish:
| infinitive | ser |
| 1st person singular | yo soy |
| 2nd person singular | tú eres / usted es |
| 3rd person singular | él / ella es |
| 1st person plural | nosotros / nosotras somos |
| 2nd person plural | ustedes son – vosotros / vosotras sois |
| 3rd person plural | ellos / ellas son |
Tener – to have: This last example is somewhat reminiscent of an -er verb in appearance, though again it’s definitely an irregular infinitive as we see through its conjugation:
| Infinitive | tener |
| 1st person singular | yo tengo |
| 2nd person singular | tú tienes |
| 3rd person singular | él / ella tiene |
| 1st person plural | nosotros / nosotras tenemos |
| 2nd person plural | ustedes tienen – vosotros / vosotras tenéis |
| 3rd person plural | ellos / ellas son |
Using the Infinitive on its own
There are instances when the Spanish infinitive is used as-is without being conjugated. These are all in compound constructions, often with some other conjugated verb working alongside the infinitive, and sometimes just with a preposition or a question word. The English translation sometimes also appears as an infinitive verb with “to,” though you’ll see that the equivalent is often an -ing form of the verb.
In this section we’ll take a look at the instances where you’re most likely to encounter Spanish infinitive verbs used in written or spoken Spanish, with plenty of examples.
Referring to an action in the near future
In English, when you’re about to do something in a short while, you may say: “I’m going to …”
It’s the same with Spanish. In this case the verb “ir” is conjugated, followed by the preposition “a” and the infinitive verb for the action in question.
- Vamos a visitar el zoológico mañana – We’re visiting the zoo tomorrow.
- Voy a comprar un carro la próxima semana – I’ll buy a car next week.
Referring to an action which has just been completed
Similarly to the previous case talking about the near future using “ir”, Spanish has a common construction for talking about the immediate past by using “acabar de…”. We conjugate the verb “acabar” for the subject, we add “de”, and then add the infinitive form of the verb describing the action we’ve just done. The English translation generally uses the word “just” to describe the timing, as seen in our examples here:
- Mi hermano acaba de llegar. – My brother just arrived.
- Acabo de elegir que ponerme esta noche. – I just chose what to wear tonight.
When following particular verbs
A lot of Spanish verbs, once conjugated, are directly followed by another verb in infinitive form.
Deber
- Deberías llamar a tu papá tan pronto como llegues a Nueva York. – You should phone your dad as soon as you arrive in New York.
Necesitar (ser necesario)
- Es necesario conducir con cuidado cuando nieva. – It is necessary to drive carefully when it ‘s snowing.
Poder
- Pedro puede correr más rápido que Bruno. – Pedro can run faster than Bruno.
Querer
- Quiero viajar a Wisconsin la próxima primavera. – I want to travel to Wisconsin next spring.
When following particular verbs with prepositions
Like the previous group, many Spanish verbs use specific prepositions followed by infinitives in order to complete their meaning. We’ll look at the prepositions a and de in this section, since they’re among the most common that follow this rule.
A
A lot of verbs take this preposition as part of their use, followed by the infinitive form of a second verb. Here’s a table of a few common Spanish a verbs, followed by several examples showing their use with infinitives.
| Infinitive + a | English |
| aprender a | to learn to |
| empezar a / comenzar a | to start to, to begin to |
| ir a | to go to |
| obligar a | to force to |
| volver a | to do something again (to back to) |
- Juan aprendió a nadar en el mar. – Juan learned to swim in the sea.
- Ellos fueron a bailar el jueves. – They went dancing on Thursday.
- Empezó a llover. – It began to rain.
- Mi equipo de fútbol volvió a perder. – My soccer team lost again.
- El juez me obligó a pagar mil dólares. – The judge forced me to pay a thousand dollars.
De
This is another very common preposition used with specific verbs, followed by an infinitive. Check out this table of some such verbs, followed by several examples.
| Infinitive + de | English |
| tratar de | to try to, |
| dejar de | to stop doing, to quit doing |
| parar de | to stop doing |
| convencer de / persuadir de | to convince/ to persuade of |
| terminar de / acabar de | to finish |
- Traté de aprender a jugar poker pero nunca aprendí – I tried to learn to play poker but I never learned
- Mi gatito paró de jugar cuando entró el perro. – My kitten stopped playing when the dog came in.
- Dejé de fumar en enero. – I quit smoking in January.
- Camilo y Lucas me convencieron de estudiar español. – Camilo and Lucas convinced me to study Spanish
- ¿Por qué no terminaste de comer la cena? – Why didn’t you finish eating dinner?
Other uses of the Spanish infinitive
We’ve covered a lot of the main rules where we use the Spanish infinitive form in written or spoken Spanish, but this list is by no means exhaustive. Here we’ll just offer some more examples of different sentences which include infinitives so you can get an idea of the variety of contexts where they’re used.
- A mis abuelos no les gusta ir a la cama sin beber una taza de té. – My grandparents don’t like going to bed without drinking a cup of tea.
- No tengo idea de qué preparar para mis suegros. – I have no idea what to prepare for my in-laws.
- A fuerza de ahorrar, mi hijo finalmente tiene suficiente dinero para comprar un auto nuevo. – By saving money, my son finally has enough money to buy a new car.
- Sin pensar, se detuvo en el camino para recoger frambuesas. – Without thinking, she stopped along the path to pick raspberries.
- Mi papá intenta irse a las 5:00 p. m., pero siempre termina trabajando más. – My dad tries to leave at 5pm, but he always ends up working more.
Conclusion
Infinitives are the base form of all verbs before any type of conjugation. In English you recognize infinitives since they’re always preceded by the word “to,” while in Spanish we recognize them since they generally occur in three categories based on their endings: -ar, -er, and -ir.
Infinitive Spanish verbs are then broken down into a stem by dropping these endings, from which the conjugations are then formed. That said, of course there are also plenty of irregular Spanish infinitives which don’t follow these rules exactly.
In a lot of situations, it’s possible to use the infinitive form directly in written or spoken Spanish, often in combination with other verbs or prepositions. We covered plenty of examples for using infinitives, including explanations of some of the most common rules. A lot of the time the English translation of the Spanish infinitive is with -ing verbs, while it’s also common to simply use the English infinitive with the word “to.”
Once you have a good grasp of infinitive Spanish, you’re ready to move on to Spanish verb conjugation. But as we saw in this post, it’s always important to first recognize the basics!