Introduction
Understanding when to use the Spanish infinitive after words like a, de, and que is essential for clear, natural Spanish. This article explains the rules, gives many examples, and shows how native speakers use these structures in everyday speech.
What is the Spanish infinitive?
The Spanish infinitive is the basic, unconjugated form of a verb: for example, hablar, comer, vivir. It functions like the English infinitive to speak, to eat, to live, but Spanish often uses the plain infinitive without the particle to. Learning when to use the infinitive after certain words keeps your sentences grammatical and natural.
General rules: when the infinitive follows another word
In Spanish, the infinitive frequently appears after prepositions, impersonal verbs, modal expressions, and as the subject or complement of a sentence. The pattern depends on the preceding word. This article focuses on three common triggers: a, de, and que.
Infinitive after the preposition a
Rule: Use the infinitive after a when a acts as a preposition that introduces a verb as an object, a purpose, or to mark motion toward an action. Common verbs and expressions that require a plus infinitive include ir a, empezar a, aprender a, ayudar a, volver a.
Examples:
Voy a estudiar esta noche.
Empezamos a cocinar temprano.
Aprendió a nadar cuando era niño.
Ella no puede a dejar — note: this is incorrect; see explanation below.
Usage notes:
1) Ir a + infinitive expresses a near future, similar to English going to. Example: Voy a salir mañana.
2) Empezar a and volver a require a before the infinitive. Example: Volvieron a hablar después de la reunión.
3) Some verbs require a preposition before another verb; pay attention to which preposition each verb takes.
Common verbs that use a plus infinitive
Here is a short list of verbs followed by a plus infinitive: aprender a, ayudar a, comenzar a, empezar a, ir a, volver a, acostumbrarse a. Example sentences:
Me ayudó a mover los muebles.
Se acostumbró a trabajar de noche.
Vamos a ver una película.
Common mistakes with a
Do not put a when the main verb requires de or no preposition. For example, dejar de + infinitive means to stop doing something: Dejé de fumar, not Dejé a fumar. Also, infinitive as a direct object often needs no preposition after verbs like querer, poder, deber: Quiero comer, Puedo ayudar.
Infinitive after the preposition de
Rule: Use the infinitive after de when de acts as a preposition linking verbs that express obligation, cessation, or when a verb requires de before another verb. Common verbs that take de include dejar de, tratar de, acabar de, olvidarse de, encargarse de, tener ganas de.
Examples:
Dejé de fumar el año pasado.
Acaba de llegar a la oficina.
Trato de leer antes de dormir.
Tengo ganas de viajar.
Usage notes:
1) Acabar de + infinitive indicates a recent action: Acabo de comer = I just ate.
2) Dejar de + infinitive means to stop doing something: Deja de llorar.
3) Tener ganas de uses de plus infinitive to express desire: Tengo ganas de salir.
Verbs that require de and meaning changes
Some verbs change meaning depending on whether you use de plus infinitive or another structure. For example, acordarse de hacer means to remember to do something: Me acordé de llamar. Olvidarse de hacer means to forget to do something: Se olvidó de pagar.
Infinitive after que
Rule: Use the infinitive after que in specific structures where que introduces the infinitive clause or when commands or impersonal expressions use an infinitive. However, more commonly, que is followed by a conjugated verb in the subjunctive. The infinitive appears after que in set phrases or in spoken, colloquial imperative forms and reduced clauses.
Examples of que plus infinitive:
Que viva el rey is not an infinitive example; here viva is subjunctive. Better examples of que plus infinitive show an imperative nuance: Que pase él is not infinitive either. Instead, see phrases like Hay que estudiar, meaning one must study. Here Hay que uses que as part of the impersonal expression; the infinitive follows directly after the phrase. Another common structure is Antes de que + subjunctive, which is followed by conjugated verbs, not infinitives.
Clarification:
In many cases where English uses that plus an infinitive, Spanish uses que plus a conjugated verb or uses the infinitive without que. For example, I want him to leave = Quiero que él se vaya (subjunctive). But I want to leave = Quiero salir (infinitive). So que does not regularly govern the infinitive; it usually introduces a clause with a conjugated verb.
When you might see que followed by an infinitive
There are limited contexts where que appears near an infinitive in everyday speech:
1) After impersonal constructions like Hay que + infinitive: Hay que hacer ejercicio.
2) In exclamations or colloquial commands where que is part of a clause and an infinitive appears later because the subject is implied: ¡Que no haber problemas! is incorrect; you would say ¡Que no haya problemas! using subjunctive.
3) Set expressions like A fin de cuentas and Antes de + infinitive use de rather than que.
Key takeaway: Learn to expect que to lead a conjugated clause; use the infinitive when the structure does not require que or when fixed impersonal phrases like Hay que exist.
Comparing a, de, and que with examples
Seeing contrasts helps. Below are parallel examples showing how meaning shifts with each word.
1) Quiero comer. (No preposition; direct desire to eat.)
2) Empiezo a comer. (I start to eat.)
3) Acabo de comer. (I just ate.)
4) Quiero que él coma. (I want him to eat; requires subjunctive, not infinitive.)
More contrasts:
1) Tengo ganas de salir. (I feel like going out.)
2) Voy a salir. (I am going to go out.)
3) Hay que salir temprano. (One must leave early.)
Practical tips to remember
1) Memorize common verbs with their required prepositions. Create small lists: verbs that take a, verbs that take de, and verbs that take no preposition before an infinitive.
2) When expressing desire, ability, obligation, or intention, check whether Spanish uses a direct infinitive (querer, poder, deber), a + infinitive (ir a, empezar a), or de + infinitive (dejar de, tratar de).
3) When in doubt and the English sentence has to or -ing, try the direct infinitive first in Spanish: Quiero estudiar, Estoy estudiando = Infinitive or gerund depending on main verb.
4) Remember that que usually introduces a clause with a conjugated verb; avoid forcing the infinitive after que unless it is part of an impersonal phrase like Hay que.
Cultural and usage notes
In spoken Spanish, contraction and omission are common. For example, Voy a estudiar often becomes Voy a estudiar or even Voy a’ estudiar in very casual speech, but the grammar remains the same. Formal writing tends to keep the preposition clear. Regional variations exist: some Latin American dialects may prefer certain verbs plus infinitive combinations more than others, but the core rules for a, de, and que are consistent across Spanish-speaking regions.
Politeness and formality also affect choices. Using Hay que + infinitive is impersonal and general. When speaking more personally, use a conjugated verb with que and subjunctive for requests or wishes: Prefiero que vengas mañana is more direct than Hay que venir mañana.
Quick reference summary
– Use a + infinitive with verbs like ir a, empezar a, aprender a, ayudar a, volver a for motion, beginnings, or assistance.
– Use de + infinitive with verbs and expressions like dejar de, acabar de, tratar de, olvidarse de, tener ganas de to indicate cessation, recent actions, attempts, forgetting, or desire.
– Use the infinitive without a preposition after verbs like querer, poder, deber, saber: Quiero leer, Puedo venir.
– Use que mainly to introduce clauses with conjugated verbs; only a few impersonal constructions like Hay que take the infinitive directly.
Conclusion
Mastering the infinitive after a, de, and que improves fluency and reduces errors. Focus on memorizing verbs with their prepositions, practicing common phrases, and noting when Spanish prefers a conjugated clause instead of an infinitive. Over time, these patterns become natural and you will recognize which structure fits each situation.
