The smallest of the three lexical-preposition groups, but no less important: a handful of high-frequency verbs in Spanish insist on the preposition en before a following infinitive. Insiste en pagar la cuenta. Pienso en cambiar de trabajo. Tardamos dos horas en llegar. Consiste en mezclar harina y agua. These are not interchangeable with a or de; each verb selects en the way English insist on, think about, take time to, consist in select their prepositions. There is some semantic coherence — most en-verbs involve focus, duration, or mental absorption — but ultimately you memorise the pairings.
The core list
The list is short enough to learn as a closed set.
| Verb + en | Meaning | Example |
|---|---|---|
| insistir en | insist on | Insiste en pagar. |
| pensar en | think about (doing) | Pienso en mudarme. |
| tardar en | take time to / be slow to | Tardé dos horas en llegar. |
| consistir en | consist of / in | Consiste en mezclar todo. |
| quedar en | agree to / arrange to | Quedamos en vernos el viernes. |
| confiar en | trust to / count on | Confío en llegar a tiempo. |
| dudar en | hesitate to | No dudes en llamarme. |
| vacilar en | hesitate to (more formal) | No vaciles en pedir ayuda. |
| esforzarse en | strive to | Se esfuerza en entenderlo. |
| empeñarse en | be determined to | Se empeña en hacerlo solo. |
| obstinarse en | be obstinate about | Se obstina en no escuchar. |
| convenir en | agree to (formal) | Convinieron en firmar el lunes. |
| coincidir en | agree on / coincide in | Coincidimos en pensar lo mismo. |
These verbs collectively cover most of the en + infinitive territory in everyday Spanish. The first four — insistir, pensar, tardar, consistir — are by far the most frequent and should be your first targets.
Cluster one: focus and insistence
These verbs describe directing one's attention or pressure onto an action.
Insistir en + infinitive
Mi suegra insiste en pagar la cuenta cada vez que cenamos fuera.
My mother-in-law insists on paying the bill every time we eat out.
Insistió en acompañarme a la estación a pesar del frío.
She insisted on going with me to the station despite the cold.
No insistas en algo que no quiere hacer.
Don't insist on something he doesn't want to do.
The English-Spanish mapping here is clean: insist on doing = insistir en doing. The trap is that English also allows insist that... with a different construction, and Spanish does too — insistir en que + subjunctive — when the subjects differ:
Insisto en que vengas a la fiesta.
I insist that you come to the party.
Same subject → insistir en + infinitive. Different subject → insistir en que + subjunctive. The preposition en stays put either way.
Empeñarse en / obstinarse en
Se empeña en hacerlo todo él solo, aunque le ofrezcan ayuda.
He's determined to do everything by himself, even when people offer help.
Te obstinas en no querer entenderme.
You're being obstinate about refusing to understand me.
Empeñarse en expresses determined commitment to an action, often slightly stubborn. Obstinarse en is stronger and more negative, closer to be pig-headed about. Both are pronominal (me empeño, te empeñas) and require en.
Esforzarse en / esforzarse por
Se esfuerza en mejorar su pronunciación todos los días.
She works hard at improving her pronunciation every day.
A tricky point: esforzarse can take either en or por + infinitive, with no real difference in meaning. Both are correct. Esforzarse por is slightly more common in formal writing; esforzarse en is more frequent in casual speech in Spain. If in doubt, por is safer in a written exam.
Cluster two: mental focus
Pensar en + infinitive: think about doing
He pensado en cambiar de trabajo, llevo años con lo mismo.
I've thought about changing jobs — I've been doing the same thing for years.
¿Has pensado alguna vez en vivir fuera de España?
Have you ever thought about living outside Spain?
Pienso en mudarme a Bilbao en septiembre.
I'm thinking about moving to Bilbao in September.
Critical to distinguish from bare pensar + infinitive, which means to plan / intend to do (covered on the after-verbs page).
Pienso ir a la playa este fin de semana.
I'm planning to go to the beach this weekend. (firm plan)
Pienso en ir a la playa este fin de semana.
I'm thinking about going to the beach this weekend. (still considering)
The presence or absence of en completely shifts the meaning of pensar: with en, it's contemplation; without, it's intention.
Confiar en + infinitive
Confío en llegar antes de que cierre la oficina.
I'm counting on getting there before the office closes.
Confiamos en encontrar una solución pronto.
We're hoping to find a solution soon.
Confiar en + infinitive expresses hope grounded in trust — "I'm counting on / trusting that I'll do X." It is slightly more formal than esperar + infinitive, and conveys more confidence.
Cluster three: duration
Tardar en + infinitive: take time to / be slow to
Tardamos dos horas en llegar al pueblo porque había caravana.
It took us two hours to get to the village because there was a traffic jam.
¿Cuánto tardas en arreglarte por las mañanas?
How long does it take you to get ready in the morning?
No tardes en venir, te estamos esperando.
Don't be long coming — we're waiting for you.
Tardar en + infinitive is one of the most useful verbs in everyday Spanish. It packages duration (how long something takes) into a single verb. The literal translation of English it takes me X to do Y — ❌me toma X hacer Y — does not exist; Spanish uses tardo X en hacer Y. The construction is unique to Spanish among the major Romance languages in this exact shape, and worth drilling.
Notice the negative imperative in the third example: no tardes en venir — "don't be slow to come" — is the standard Spanish way to say "come soon" or "don't take long." It's the same pattern as no dejes de (don't fail to) from the de-verb page.
Vacilar en / dudar en + infinitive: hesitate to
No dudes en preguntarme si tienes cualquier duda.
Don't hesitate to ask me if you have any question.
No vaciles en llamarnos a cualquier hora del día.
Don't hesitate to call us at any time of day.
Both verbs mean hesitate to. Vacilar en is slightly more formal and literary; dudar en is everyday. In peninsular Spanish, no dudes en + infinitive is a polite formula heard constantly in customer-service contexts ("don't hesitate to contact us"). Note: vacilar in colloquial peninsular Spanish has a separate slang meaning — "to tease" or "to mock" — but that is the bare verb (me estás vacilando = "you're pulling my leg"), not the vacilar en construction.
Cluster four: agreement and composition
Quedar en + infinitive: agree to / arrange to
Quedamos en vernos el viernes a las siete delante del cine.
We agreed to meet on Friday at seven in front of the cinema.
¿En qué quedamos al final?
So what did we end up agreeing on?
Quedar en + infinitive is the workhorse for arranging a meeting or making a verbal agreement in Spain. It is distinct from bare quedar (= "to meet up" or "to remain") and from quedarse (= "to stay"). The construction is everywhere in peninsular Spanish: quedamos en cenar el sábado, quedaron en hablarlo la semana que viene, ¿en qué habíamos quedado?
Consistir en + infinitive: consist of doing
El truco consiste en batir las claras a punto de nieve.
The trick is to whisk the egg whites until stiff.
Su trabajo consiste en revisar todos los contratos antes de firmarlos.
Her job consists of reviewing all contracts before they're signed.
Consistir en tells you what something is made of or what it amounts to. Note that English uses consist of (with of) but Spanish uses consistir en (with en) — a classic mismatch that produces ❌consistir de in learner Spanish. Watch for it.
Convenir en / coincidir en + infinitive
Convinieron en firmar el acuerdo el lunes siguiente.
They agreed to sign the agreement the following Monday. (formal)
Todos coincidimos en pensar que era una mala idea.
We all agreed in thinking it was a bad idea.
Convenir en is the formal version of quedar en — you'll see it in legal contexts and journalism, rarely in conversation. Coincidir en means "agree (on the same view)" and is used when expressing a shared opinion.
The English-mismatch problem
The en-verbs are particularly prone to producing literal-translation errors because English and Spanish each have a small inventory of "lexically required" prepositions, and they only partly overlap.
| English verb + preposition | Spanish verb + preposition |
|---|---|
| insist on doing | insistir en hacer (match) |
| think about doing | pensar en hacer (mismatch: about → en) |
| consist of | consistir en (mismatch: of → en) |
| hesitate to | dudar en / vacilar en (mismatch: to → en) |
| take time to | tardar en (mismatch: no English equivalent for this exact structure) |
| agree to do | quedar en hacer / convenir en hacer |
The only safe approach is to memorise the Spanish verb + preposition together, treating them as a single lexical entry: insistir-en, pensar-en, tardar-en, consistir-en. Trying to translate from English will produce errors more often than not.
A note on que-clauses with en-verbs
When the subjects differ, the en preposition stays and que follows it.
Insiste en pagar.
He insists on paying. (same subject)
Insiste en que pagues tú.
He insists that you pay. (different subject — subjunctive)
Confío en que llegues a tiempo.
I'm counting on you arriving on time.
This en que + subjunctive pattern is the most common shape you'll meet with en-verbs at B2. Don't drop the en — ❌insiste que pagues is wrong.
A register note: esforzarse en vs esforzarse por
We mentioned this above, but it bears repeating: esforzarse is one of the few Spanish verbs that allows two prepositions before its infinitive complement, with no real semantic difference.
Se esfuerza en aprender alemán.
She works hard at learning German.
Se esfuerza por aprender alemán.
She works hard to learn German.
Both are correct. Both are common in Spain. If you're writing a formal text, por is slightly preferred by the RAE; in everyday speech, en is just as natural.
Common Mistakes
❌ Pienso a cambiar de trabajo.
Wrong — pensar takes en when it means 'think about'.
✅ Pienso en cambiar de trabajo.
I'm thinking about changing jobs.
❌ Insiste pagar la cuenta.
Wrong — insistir requires en.
✅ Insiste en pagar la cuenta.
He insists on paying the bill.
❌ Tardamos dos horas a llegar.
Wrong — tardar takes en, not a.
✅ Tardamos dos horas en llegar.
It took us two hours to arrive.
❌ El trabajo consiste de revisar contratos.
Wrong — consistir takes en, not de. (English 'consist of' is a false friend.)
✅ El trabajo consiste en revisar contratos.
The job consists of reviewing contracts.
❌ Quedamos a vernos el viernes.
Wrong — quedar takes en when arranging a plan.
✅ Quedamos en vernos el viernes.
We agreed to meet on Friday.
Key takeaways
- A small but high-frequency closed list of Spanish verbs takes en before an infinitive. The most important are insistir en, pensar en, tardar en, consistir en, quedar en, confiar en, dudar en.
- Watch for the meaning shift in pensar: bare pensar
- infinitive = "plan to," pensar en
- infinitive = "think about."
- infinitive = "plan to," pensar en
- Tardar en
- infinitive is the standard Spanish way to express duration ("it takes me X to do Y"); learn it as a fixed construction.
- English-Spanish preposition mappings often mismatch — consist of becomes consistir en, hesitate to becomes dudar en. Memorise verb + preposition pairs as single units.
- With different subjects, the en stays and que follows it (insistir en que
- subjunctive).
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- Infinitivo después de verbos conjugadosA2 — When two verbs share a subject, the second one stays in the infinitive — quiero ir, puedo venir, suelo madrugar — never que, never a conjugated form.
- Verbos seguidos de 'a' + infinitivoB1 — Verbs that lexically require 'a' before an infinitive — empezar a, aprender a, ayudar a, atreverse a — usually involve motion, initiation, learning or commitment toward an action.
- Verbos seguidos de 'de' + infinitivoB1 — Verbs that demand 'de' before an infinitive — acabar de, dejar de, tratar de, acordarse de — cluster around stopping, completing, remembering, and trying.
- Verbos con preposición 'en'B1 — A closed list of Spanish verbs requires the preposition 'en' before their complement — pensar en, insistir en, consistir en, fijarse en, entrar en. Most cluster around focus, insistence, conversion, and trust, and the English-Spanish preposition mapping rarely matches.