Spanish infinitives after prepositions explained for English speakers

Introduction

Understanding how to use Spanish infinitives after prepositions is one of the quickest ways to sound more natural and accurate. This guide explains the rules, common prepositions, subtle differences with English, and plenty of clear examples to help English-speaking learners feel confident when using infinitives after prepositions in Spanish.

What is an infinitive and why it matters after prepositions

An infinitive is the basic, unconjugated form of a verb: hablar, comer, vivir. In English we often say to speak, to eat, to live. In Spanish, after a preposition you almost always use the infinitive, not a conjugated verb. This simple rule makes Spanish sentences more predictable and avoids verb agreement mistakes.

Key rule

After a preposition, use the infinitive form of the verb. For example: pensar en + infinitive, antes de + infinitive, después de + infinitive. The infinitive acts like a noun in these constructions, which is different from English where we often use a gerund with -ing.

Common Spanish prepositions followed by infinitives

Some prepositions always require an infinitive in Spanish. Learning these will cover most everyday situations.

antes de and después de

Use antes de to say before doing something, and después de to say after doing something. Both must be followed by an infinitive.

Examples:
Antes de salir, apaga las luces.
Después de comer, vamos al cine.

para

Para expresses purpose or intention and is followed by an infinitive. This corresponds to in order to or to in English.

Examples:
Estudio para aprender español.
Traje agua para beber.

por (when expressing reason or cause)

When por indicates reason and is followed by a verb, Spanish uses a noun or an infinitive phrase rather than a conjugated verb. Use the infinitive to convey because of doing something or due to doing something.

Examples:
Cancelaron el vuelo por llegar tarde del equipo técnico. (because of the technical team arriving late)
La casa está sucia por no limpiar durante semanas.

sin

Sin means without and must be followed by an infinitive when indicating something was done without doing something else.

Examples:
Salió sin decir adiós.
No puedo estudiar sin escuchar música.

al + infinitive

The combination al + infinitive expresses when something happens upon or at the moment of doing something. It is a contraction of a + el followed by an infinitive acting like a noun phrase.

Examples:
Al llegar, llamó a su madre.
Al abrir la puerta, escuchamos música.

Prepositions that require a noun or pronoun before the infinitive

Some prepositions are followed by a noun, pronoun, or a verb in the infinitive but sometimes require changes depending on whether the subject of the preposition matches the main clause subject.

de + infinitive after verbs expressing emotions or perceptions

When using verbs like alegrarse, preocuparse, tener miedo, or darse cuenta, Spanish often uses de before a noun or infinitive. If the subject of the main verb and the action are the same, an infinitive follows. If they differ, a subordinate clause with que and conjugated verb is used.

Examples (same subject):
Me alegro de verte.
Se enojó de perder el partido. (less common; more natural: Se enojó por perder el partido)

Examples (different subjects):
Me alegro de que tú vengas. (not an infinitive because subjects differ)

Prepositions that change meaning with infinitive vs clause

Some constructions allow both an infinitive and a subordinate clause but with subtle meaning differences or strict subject agreement rules. Pay attention to whether the action belongs to the same subject as the main verb.

Differences between English gerunds and Spanish infinitives

In English, after prepositions we commonly use the gerund -ing. For example: I am excited about meeting you. Spanish does not use gerunds the same way; instead you almost always use an infinitive after the preposition.

Comparison:
I am good at cooking. -> Soy bueno en cocinar.
I am interested in learning Spanish. -> Estoy interesado en aprender español.

Note that while English uses about + gerund, Spanish uses en + infinitive or estar interesado en + infinitive.

When you cannot use an infinitive after a preposition

Not every situation allows an infinitive. If the subject after the preposition differs from the main clause subject, Spanish typically requires a full clause with que and a conjugated verb, or a prepositional phrase with de + noun.

Different subjects: use que + subjunctive or indicative

If the subject of the action is different, use que and conjugate. Choose subjunctive or indicative based on mood rules (desire, doubt, emotion -> subjunctive; factual statements -> indicative).

Examples:
Quiero que tú vengas mañana. (different subject -> que + subjunctive)
Estoy seguro de que él vendrá. (different subject, certainty -> que + indicative)

Using a noun instead of an infinitive

Sometimes a noun or nominalization is preferred. Instead of using a verb directly, Spanish uses a noun introduced by de or sin.

Examples:
La idea de viajar me emociona. (The idea of traveling excites me.)
El problema de fumar en casa es obvio.

Practical examples grouped by common prepositions

Seeing grouped examples helps internalize patterns. Each block below shows a preposition followed by typical infinitive uses.

antes de / después de

Antes de estudiar, revisa la tarea.
Después de llamar, apaga el teléfono.

para

Trabajo para pagar las cuentas.
Entrena para correr la maratón.

por

Lo felicitaron por ganar el premio.
Se quedó en casa por no sentirse bien.

sin

No salgas sin terminar la tarea.
Bebimos café sin hablar mucho.

al + infinitive

Al ver la noticia, se sorprendió.
Al terminar la reunión, enviaron el informe.

Common pitfalls for English speakers

English speakers often slip into incorrect forms because English uses -ing forms or full infinitives with to. Watch for these common mistakes and correct them with Spanish-friendly options.

Incorrect transfer of English gerund

Incorrect: Estoy interesado en learning español.
Correct: Estoy interesado en aprender español.

Incorrect use of to + infinitive structure

Incorrect: Antes de to comer, lavarse las manos.
Correct: Antes de comer, lávate las manos.

Forgetting subject agreement

When subjects differ, do not use an infinitive. Use que + conjugated verb instead.

Incorrect: Quiero que dejar ahora. (wrong when subject differs)
Correct: Quiero que dejes ahora.

Stylistic notes and regional usage

Spanish in different countries may vary slightly in prepositional choices or colloquial preferences. For example, some speakers prefer por + infinitive in certain causal phrases, while others choose de + noun. Familiar exposure through listening and reading will help you sense regional tendencies.

Formal vs informal style

In formal writing, infinitives after prepositions are especially common and clear. In informal speech, you might hear more contractions, omissions, or relaxed syntax, but the rule of using the infinitive after prepositions remains robust.

Pronunciation tip

When a preposition is followed by an infinitive, native speakers often connect the words smoothly. Practice saying phrases like para estudiar, sin dormir, antes de salir to build fluidity and natural rhythm.

Quick reference chart

Use this mental checklist when you face a preposition:

If the preposition appears, prefer the infinitive: antes de, después de, para, sin, por (causal), al + infinitive.
If the subject of the action differs from the main clause, use que + conjugated verb (choose subjunctive or indicative appropriately).
If a noun fits better, use de + noun or another nominalization.

Applying the rule in real conversation

Try to notice infinitives after prepositions in songs, TV shows, and podcasts. You will see phrases like antes de salir, para entender, sin decir nada, and al entrar repeatedly. These chunks are high-frequency and will quickly boost comprehension and speaking ability.

Conclusion

Mastering the use of Spanish infinitives after prepositions is a powerful step for English-speaking learners. Remember the central rule: after most prepositions use the infinitive. Pay attention to subject differences that require que + conjugated verb, and practice common preposition + infinitive pairs. With exposure and practice you will start producing natural, grammatically correct sentences with confidence.