Understanding and Using Infinitives

Infinitives Have Characteristics of Nouns and Verbs

Sign showing use of Spanish infinitive
Prohibido botar basura. (Dumping garbage prohibited.) Sign is from Navidad, Chile. The infinitive in the sentence is "botar.". Javier Ignacio Acuña Ditzel/Creative Commons.

Definition of 'Infinitive'

The infinitive is the most basic form of a verb. In Spanish, infinitives always end in -ar, -er or -ir, with -ar being the most common. In English, "infinitive" is usually used to refer to the "to + verb" form of the verb such as "to run" or "to eat," although according to some authorities the infinitives are "run" and "eat."

An infinitive by itself does not indicate tense nor who or what is performing the action of the verb.

In both English and Spanish, the infinitive can often function as a noun. In Spanish, such a noun is always masculine and is usually used in the singular form.

The Spanish word for "infinitive" is infinitivo.

Other examples of infinitives in Spanish are hablar, viajar, comprender, and resistir. The corresponding English infinitives are "to speak," "to travel," "to understand," and "to resist."

Using Infinitives as the Subject of a Sentence

It is very common in Spanish for an infinitive to be the subject of a sentence or clause. In translation to English, either the infinitive or the gerund can be used, although Spanish gerunds can't function as nouns. For example, the sentence "Salir es difícil" could be translated as either "To leave is difficult" or "Leaving is difficult." Often when an infinitive is the subject, it can follow the verb. Thus it would be possible to render the Spanish sentence as "Es difícil salir.


  • Amar is mejor que ser amado. (To love is better than being loved.)
  • No es posible comer todo el día de manera saludable. (Eating all day is not possible in a healthy way. Alternative translation: It is not possible to eat all day in a healthy way.)
  • El ser humano comparte muchas características con los primates. (The human being shares many characteristics with the primates.)

    Using Infinitives as Prepositional Objects

    In Spanish but not usually in English, infinitives are often the objects of prepositions. The gerund is typically used in translation to English.

    • Tu hija tiene ya la capacidad para entender tus reglas. (Your daughter doesn't yet have the capacity for understanding your rules. Para is the preposition here.)
    • El tenista confirmó que le ofrecieron dinero por perder un partido. (The tennis player confirmed that they offered him money for losing a match. The preposition here is por.)

    Using Infinitives as a Verbal Object

    In a sentence such as "Espero comprar una casa" (I hope to buy a house), the infinitive in both language retains qualities of both noun and verb — noun because it's an object and a verb because hit as an object of its own (una casa or "a house").

    • Ayer te vi salir de tu oficina. (Yesterday I saw you leaving your office.)
    • Necesito cambiar el nombre de usuario. (I need to change my user name.)
    • Quiero to eat pronto. (I want to eat soon.)

    Using Infinitives as a Verbal Complement

    Infinitives are often used as the complement of a copulative or linking verb: This is especially common with forms of ser, meaning "to be."

    • Lo más importante es saber que usted no estás sola. (The most important thing is to know you are not alone.)
    • Todo lo que yo quería era hablar contigo. (All that I wanted was to talk with you.)
    • Katarina me parece ser una buen artista. (Katarina seems to me to be a good artist.)

    Infinitives as Commands

    In Spanish, it is common in recipes and on signs, less so in speech, to use an infinitive as a type of command. Such a construction is rare in English with the exception of this negative command: "Not to worry."

    • Mezclar los ingredientes en el siguiente orden. (Mix the ingredients in the following order.)
    • No fumar. (No smoking.)

    Forming a Future Tense Using Infinitives

    The periphrastic future tense is common in both Spanish and English. It is formed by using a present tense of ir a or "to go" followed by an infinitive. In some Spanish-speaking areas, the periphrastic future has mostly replaced the conjugated future tense.

    In both languages, it is considered less formal than the standard future tense.

    • Van a estudiar las principales teorías. (They are going to study the principal theories.)
    • Voy a probarlo una vez. (I'm going to try it once.)