Infinitives after prepositions

Infinitives after prepositions in Spanish

Spanish rule in one line: when a verb follows a preposition, use the infinitive form (hablar, comer, vivir). This article explains what that means, when and why you use it, how to form it, common verbs and prepositions that take an infinitive, pronunciation notes about pronouns, and frequent mistakes. Examples are given in Spanish with English translations.

What does this mean?

A preposition (a, de, en, para, por, sin, antes de, después de, etc.) connects words or phrases. When what comes after a preposition is a verb, Spanish requires the verb to be in the infinitive (the unconjugated form): comer, hablar, vivir. The infinitive in this case functions like a noun.

Examples:

- "Antes de comer, me lavé las manos." (Before eating, I washed my hands.)
- "Sin decir nada, se fue." (Without saying anything, he left.)
- "Gracias por venir." (Thanks for coming.)
- "Voy a estudiar." (I am going to study.)

Note about English: after prepositions English usually uses the -ing form (gerund): before eating, after leaving, without saying. In Spanish you use the infinitive instead.

When and how do I use infinitives after prepositions?

General rule

After any preposition (simple or compound), if the next element is a verb, use the infinitive form.

- "Antes de salir, apaga la luz." (Before leaving, turn off the light.)
- "Estudio para aprender." (I study to learn.)
- "Se fue sin avisar." (He left without warning.)

Common prepositions that take an infinitive (with examples)

- a
- "Aprendí a nadar." (I learned to swim.)
- "Me ayudó a terminar el trabajo." (He helped me finish the job.)
- "Voy a estudiar." (I’m going to study.)

- de
- "Antes de comer, me lavo las manos." (Before eating, I wash my hands.)
- "Acabo de llegar." (I have just arrived.)
- "Estoy cansado de esperar." (I’m tired of waiting.)

- para (purpose)
- "Estudia para aprobar el examen." (He studies in order to pass the exam.)
- "Lo hice para ayudarte." (I did it to help you.)

- por (reason/cause)
- "Gracias por venir." (Thanks for coming.)
- "Lo criticaron por llegar tarde." (They criticized him for arriving late.)

- sin (without)
- "Se fue sin despedirse." (He left without saying goodbye.)
- "Sin pensarlo, saltó." (Without thinking, he jumped.)

- antes de / después de
- "Antes de dormir, leo un libro." (Before sleeping, I read a book.)
- "Después de terminar, te llamo." (After finishing, I’ll call you.)

- al (a + el) + infinitive — means "upon / on doing"
- "Al llegar, me quité los zapatos." (Upon arriving, I took off my shoes.)

- hasta
- "No me voy hasta terminar." (I won’t leave until finishing.)

- en vez de / en lugar de (instead of)
- "En vez de quejarte, actúa." (Instead of complaining, act.)

- tras (formal "after")
- "Tras pensarlo, aceptó la oferta." (After thinking about it, he accepted the offer.)

When the subject is the same vs. when it’s different

Key idea: preposition + infinitive is allowed when the subject of the infinitive and the subject of the main clause are the same. If the subject changes, you usually need a clause with "que" + subjunctive (or another full clause).

Same subject (use preposition + infinitive):

- "Antes de irme, te llamé." (Before leaving, I called you.) — both actions are done by the same person (I).
- "Estudié para aprobar el examen." (I studied to pass the exam.) — same subject.

Different subjects (use que + subjunctive or a full clause):

- "Salí antes de que ella llegara." (I left before she arrived.) — different subjects → "antes de que" + subjunctive.
- "Te lo digo para que lo hagas mañana." (I’m telling you so that you do it tomorrow.) — different subjects → "para que" + subjunctive.
- "Se fue sin que nadie se diera cuenta." (He left without anyone realizing it.) — "sin que" + subjunctive.

Short rule of thumb:
- Same subject → preposition + infinitive.
- Different subjects → preposition + que + subjunctive (typical for antes de que, para que, sin que, etc.).

Special note on "al + infinitive"

"Al" + infinitive means "upon/when [doing something]" and normally implies the subject is the same as the main clause. If subjects differ, prefer "cuando" or a clause with a conjugated verb.

- Correct (same subject): "Al entrar en casa, me quité los zapatos." (When I entered the house, I took off my shoes.)
- If subjects differ, say: "Cuando entró María, saludé a todos." (When María entered, I greeted everyone.)

Pronouns with infinitives after prepositions

When you have a preposition + infinitive and you need an object pronoun, attach the pronoun to the infinitive.

- "Antes de irme, te llamé." (Before leaving, I called you.) — "irme" = ir + me
- "Gracias por ayudarme." (Thanks for helping me.) — "ayudarme" = ayudar + me
- "Después de verlo, entendí la situación." (After seeing him, I understood the situation.) — "verlo" = ver + lo

You can also place the pronoun before a conjugated verb if there is no preposition: "Te voy a llamar" or attach it to the infinitive: "Voy a llamarte." But after a preposition, the pronoun goes after the infinitive.

Common verbs and adjectives that link to an infinitive (patterns to learn)

Many verbs and adjectives in Spanish are followed by a specific preposition plus an infinitive. Memorize common pairs:

Verbs + a + infinitive:
- aprender a: "Aprendí a tocar la guitarra." (I learned to play guitar.)
- ayudar a: "Me ayudó a escribir el informe." (He helped me write the report.)
- empezar/comenzar a: "Empezó a llover." (It began to rain.)
- volver a (do again): "Volvió a intentarlo." (He tried again.)

Verbs + de + infinitive:
- acabar de + infinitive (just finished): "Acabo de comer." (I just ate.)
- dejar de + infinitive (stop doing): "Dejé de fumar." (I stopped smoking.)
- tratar de + infinitive (try to): "Trato de dormir temprano." (I try to sleep early.)
- olvidarse de + infinitive: "Me olvidé de llamar." (I forgot to call.)

Adjectives + preposition + infinitive:
- estar cansado de: "Estoy cansado de esperar." (I’m tired of waiting.)
- listo/ preparado para: "Estoy listo para salir." (I’m ready to leave.)
- fácil/difícil de: "La tarea es fácil de hacer." (The homework is easy to do.)

Note: some verbs that in English take "to + infinitive" do not need a preposition in Spanish (e.g., "quiero ir", "puedo hacerlo"). Learn each verb's pattern.

Common mistakes and how to fix them

1) Using an English-style gerund (-ing) after a preposition:
- Incorrect: "Después de yendo a la tienda..."
- Correct: "Después de ir a la tienda..." (After going to the store...)

2) Using a conjugated verb after a preposition when the subject is the same (or mixing subjects incorrectly):
- Incorrect: "Antes de que yo voy..."
- Correct (same subject, simpler): "Antes de ir..." (Before going...)
- Correct (different subject): "Antes de que yo vaya..." (Before I go... — note subjunctive)

3) Confusing para and por:
- Incorrect: "Estudio por aprobar el examen."
- Correct: "Estudio para aprobar el examen." (para = purpose; por would mean reason or cause)

4) Wrong placement of object pronouns after preposition + infinitive:
- Incorrect: "Antes de lo ver."
- Correct: "Antes de verlo." (Before seeing him.)

5) Trying to use "al + infinitive" when subjects differ (it can be ambiguous):
- Prefer: "Cuando yo entré, ella me llamó." instead of an ambiguous "Al entrar, ella me llamó."

Quick reference: common structures (with short examples)

- antes de + infinitive — "Antes de salir, cierra la puerta." (Before leaving, close the door.)
- después de + infinitive — "Después de comer, paseamos." (After eating, we walked.)
- sin + infinitive — "Se fue sin avisar." (He left without warning.)
- para + infinitive — "Trabajo para ganar dinero." (I work to earn money.)
- por + infinitive — "Lo felicitaron por llegar primero." (They congratulated him for arriving first.)
- a + infinitive — "Empezó a llover." (It began to rain.)
- al + infinitive — "Al salir, cerró la ventana." (Upon leaving, he closed the window.)
- en vez de / en lugar de + infinitive — "En lugar de llorar, actúa." (Instead of crying, act.)
- hasta + infinitive — "No me fui hasta terminar." (I didn’t leave until finishing.)

Glossary (simple definitions)

- Infinitive (infinitivo): the basic, unconjugated verb form (comer, hablar, vivir).
- Preposition (preposición): a word that links items (a, de, en, para, por, sin, antes de, etc.).
- Gerund (gerundio): Spanish "-ando / -iendo" form (comiendo, hablando); not used after prepositions the same way as English.
- Subjunctive (subjuntivo): verb mood used after expressions that indicate doubt, desire, or when subjects change in subordinate clauses.
- Clitic pronouns: object pronouns that attach to infinitives (me, te, lo, la, nos, os, los, las).

Final tips / summary

- After a preposition, use the infinitive (comer, salir, decir). English speakers often try to use -ing; don’t do that in Spanish.
- If the subject of the prepositional idea is different from the main clause subject, you usually must use "que + subjunctive" (e.g., "para que", "antes de que", "sin que").
- Attach object pronouns to the infinitive when you have a preposition + infinitive ("antes de verlo", "gracias por ayudarme").
- Learn common verb+preposition patterns (aprender a, acabar de, dejar de, tratar de, estar cansado de, listo para).

With practice, recognizing prepositions and the subject of each clause will make using the infinitive straightforward. When in doubt, ask: who is doing the action? If it’s the same subject, use preposition + infinitive; if not, use a clause with "que" + subjunctive (or another full clause). Good luck!