Aprendí a nadar cuando tenía seis años.I learned to swim when I was six.

Many Spanish verbs can be followed by a second verb in the infinitive, but the way the two connect isn't always the same. Some verbs need a in between, some need de, a few need en, and others connect with no preposition at all. Which one a given verb takes isn't something you can predict from its meaning — it has to be learned verb by verb, though a few loose patterns help: a often goes with starting, moving toward or teaching something; de often goes with stopping, finishing or remembering; en often goes with hesitating, taking time or agreeing. None of these patterns are exceptionless, so the safest approach is still to learn each verb with its preposition as a single unit.

Quick shortcut: empezar a, aprender a (a); dejar de, tratar de (de); tardar en, insistir en (en); querer, poder, decidir (no preposition). Learn each verb together with its preposition, not separately.

Verbs + a + infinitive

Verb Meaning Example
empezar a / comenzar a to start doing Empezó a llover. (It started to rain.)
aprender a to learn to do Aprendí a nadar. (I learned to swim.)
enseñar a to teach someone to do Mi padre me enseñó a conducir. (My father taught me to drive.)
ayudar a to help do Me ayudó a mudarme. (He helped me move.)
invitar a to invite someone to do Nos invitó a cenar. (She invited us to dinner.)
atreverse a to dare to do No se atreve a hablar en público. (He doesn't dare speak in public.)
decidirse a to make up one's mind to do Por fin se decidió a viajar sola. (She finally made up her mind to travel alone.)
negarse a to refuse to do Se negó a firmar el contrato. (He refused to sign the contract.)

Empezar a and volver a and ir a already have their own lessons, since each adds its own extra shade of meaning beyond just "verb + a + infinitive" — the pattern here is the same connecting preposition, just without that extra meaning layered on.

Verbs + de + infinitive

Verb Meaning Example
dejar de to stop doing Dejó de fumar. (He stopped smoking.)
tratar de to try to do Trataron de convencerme. (They tried to convince me.)
terminar de to finish doing Terminé de leer el libro. (I finished reading the book.)
acordarse de to remember to do Acuérdate de cerrar la puerta. (Remember to close the door.)
olvidarse de to forget to do Me olvidé de llamarte. (I forgot to call you.)
arrepentirse de to regret doing Se arrepiente de haber mentido. (He regrets having lied.)

Dejar de also has its own lesson, as part of the same set of two-verb constructions as empezar a above. Acabar de + infinitive is a different construction worth keeping separate from this list — it doesn't mean "to finish doing," it means "to have just done" something (Acabo de llegar, "I've just arrived"), covered in its own lesson.

Verbs + en + infinitive

Verb Meaning Example
tardar en to take time to do Tardó dos horas en llegar. (It took him two hours to arrive.)
insistir en to insist on doing Insistió en pagar la cuenta. (He insisted on paying the bill.)
pensar en to think about doing Estoy pensando en cambiar de trabajo. (I'm thinking about changing jobs.)
quedar en to agree to do Quedamos en vernos a las ocho. (We agreed to meet at eight.)
consistir en to consist of doing El trabajo consiste en atender llamadas. (The job consists of answering calls.)
dudar en to hesitate to do No dudó en ayudarnos. (She didn't hesitate to help us.)

No preposition at all

A large group of common verbs connect straight to the infinitive, with nothing in between:

Quiero viajar este verano. (I want to travel this summer.) No puedo venir mañana. (I can't come tomorrow.) Decidió estudiar medicina. (He decided to study medicine.)

This group includes querer, poder and deber, plus necesitar, decidir, preferir, desear, esperar, intentar, lograr and conseguir. Decidir is worth a specific mention for English speakers coming from other Romance languages: it connects directly, with no preposition at all — decidir viajar, not decidir a viajar or decidir de viajar.

Same verb, different preposition, different meaning

A few verbs change meaning depending on which preposition follows, or whether one follows at all:

  • pensar + infinitive (to intend to do something) vs. pensar en + infinitive (to think about / be considering doing something): Pienso viajar a España el próximo verano. (I intend to travel to Spain next summer — it's decided.) Estoy pensando en viajar a España. (I'm thinking about traveling to Spain — not decided yet.)
  • acabar por + infinitive (to end up doing something) vs. acabar de + infinitive (to have just done something): Acabó por mudarse a otra ciudad. (She ended up moving to another city.) Acaba de mudarse a otra ciudad. (She has just moved to another city.)

Common mistakes

  • ❌ Empecé estudiar español. → ✅ Empecé a estudiar español. (empezar needs a before the infinitive — it doesn't connect directly.)
  • ❌ Dejé a fumar. → ✅ Dejé de fumar. (dejar takes de, not a.)
  • ❌ Quiero a nadar. → ✅ Quiero nadar. (querer connects straight to the infinitive, with no preposition at all.)
  • ❌ Pienso en viajar a España el verano que viene, meaning "I've made up my mind" → ✅ Pienso viajar a España el verano que viene. (adding en turns a firm intention into "I'm considering it" — a real difference in meaning, not just a style choice.)

Quick check

  1. Complete with the right preposition, or none: Aprendí ___ tocar la guitarra.
  2. Complete with the right preposition, or none: Dejó ___ trabajar aquí el año pasado.
  3. Complete with the right preposition, or none: No puedo ___ ir a la fiesta.
  4. What's the difference between pienso viajar and pienso en viajar?
Show answers
  1. Aprendí a tocar la guitarra.
  2. Dejó de trabajar aquí el año pasado.
  3. No puedo ir a la fiesta. (poder connects directly, with no preposition.)
  4. Pienso viajar means the trip is a firm intention; pienso en viajar means it's just an idea being considered.

Key takeaways

  • Which preposition links a verb to a following infinitive — a, de, en, or none at all — has to be learned with the verb itself; it isn't predictable from meaning alone.
  • Loose patterns: a often goes with starting, moving toward or teaching something; de with stopping, finishing or remembering; en with hesitating, taking time or agreeing — but none of these are exceptionless.
  • A large set of common verbs (querer, poder, deber, decidir, necesitar...) connect straight to the infinitive with no preposition at all.
  • A few verbs change meaning with the preposition: pensar (intend) vs. pensar en (consider), acabar (end up) vs. acabar de (have just done).