Most learners spend a lot of time on verbs followed by de (acordarse de, dejar de) and a (empezar a, aprender a) because those two prepositions dominate the system. But Spanish also has two smaller, very productive groups: verbs that take con + infinitivo and verbs that take por + infinitivo. They are smaller, but the verbs in them — soñar con, contar con, optar por, esforzarse por — are extremely common in everyday speech and in journalism. Getting these prepositions right is a sharp marker of B2-and-above fluency.
How these constructions work
In both cases, the structure is fixed: conjugated verb + preposition + infinitivo. The preposition belongs to the main verb (it is part of the verb's lexical entry, like the on in English count on), and the infinitive is whatever action the construction is about. The subject of the infinitive is the same as the subject of the main verb: Sueño con vivir en Madrid — the dreamer and the would-be Madrid resident are the same person. When the subjects differ, Spanish switches to preposición + que + a conjugated verb (typically subjunctive): Cuento con que vengas mañana — "I'm counting on you to come tomorrow."
Verbs that take con + infinitivo
The con group is small but its members are heavy hitters. The semantic thread running through it is mental engagement with a future or hypothetical action — dreaming, counting on, threatening, being content with. Con here is the same preposition that means with, but the meaning has been bleached and grammaticalised.
soñar con + infinitivo — to dream of doing
The single most common verb in this group. Soñar con means to dream of / about, and when the dream is an action, the infinitive follows.
Sueño con vivir en Madrid algún día.
I dream of living in Madrid one day.
De pequeña soñaba con ser astronauta.
As a little girl I dreamed of being an astronaut.
Note the error trap: never *soñar de or *soñar a. Always soñar con.
contar con + infinitivo — to count on doing / to be counting on (someone's) doing
Contar con literally is to count with; functionally it means to count on in the sense of to rely on, to expect. With an infinitive it expresses what you are counting on happening.
Contamos con terminar la mudanza este fin de semana.
We're counting on finishing the move this weekend.
No contaba con tener que trabajar el sábado.
I wasn't counting on having to work on Saturday.
amenazar con + infinitivo — to threaten to do
A verb whose meaning is almost identical to the English threaten to, but with the very different preposition con.
El jefe amenazó con despedirnos a todos si no entregábamos el proyecto.
The boss threatened to fire us all if we didn't deliver the project.
La tormenta amenaza con dejarnos sin luz toda la noche.
The storm is threatening to leave us without power all night.
contentarse con / conformarse con + infinitivo — to be content with / to settle for doing
Contentarse con means to be satisfied with something less than the ideal. Conformarse con is its near-synonym, slightly more resigned in tone.
Me contento con aprobar; no necesito sacar sobresaliente.
I'm happy just to pass; I don't need to get top marks.
Tendremos que conformarnos con ver la final por la tele.
We'll have to settle for watching the final on TV.
Other useful con verbs
- acabar con
- bastar con
- atreverse a — does NOT take con; flagged here because learners often confuse the prepositions.
Basta con llamar y te traen la cena a casa.
It's enough to call and they'll bring dinner to your house.
Verbs that take por + infinitivo
The por group has its own semantic thread: choice, effort, and the endpoint of a process. Por here often answers for what reason or in favour of what option — it is the por of motive and choice rather than the por of duration or location.
optar por + infinitivo — to choose / opt for doing
A high-register but extremely common verb in journalism, business, and educated speech. It frames a decision as a deliberate selection among options.
Al final optamos por quedarnos en casa y pedir pizza.
In the end we chose to stay home and order pizza.
El gobierno ha optado por subir los impuestos en lugar de recortar el gasto.
The government has opted to raise taxes instead of cutting spending.
terminar por / acabar por + infinitivo — to end up doing
These two are near-synonyms — terminar por is slightly more formal in Spain, acabar por more colloquial — and both translate the English end up + -ing. They express that after a process, deliberation, or resistance, someone finally arrived at an action.
Después de tanta discusión, terminaron por aceptar la propuesta.
After so much arguing, they ended up accepting the proposal.
Acabé por irme a la cama sin cenar.
I ended up going to bed without dinner.
empezar por / comenzar por + infinitivo — to begin by doing
These two follow the same logic in reverse: instead of marking the endpoint of a process, they mark its starting point. Note the contrast with empezar a + infinitive (to start doing), which is plain inceptive aspect; empezar por foregrounds a sequence ("first thing I did was...").
Empieza por leer las instrucciones antes de montar el mueble.
Start by reading the instructions before assembling the furniture.
Comenzaré por agradecer a todos los presentes.
I'll begin by thanking everyone here.
esforzarse por + infinitivo — to strive / make an effort to do
A verb that captures sustained effort toward a goal. Esforzarse en is also heard, but esforzarse por is the dominant peninsular norm.
Se esfuerza por aprender cinco palabras nuevas cada día.
She makes an effort to learn five new words every day.
Nos esforzamos por entender su punto de vista, aunque no estábamos de acuerdo.
We tried hard to understand his point of view, even though we didn't agree.
apostar por + infinitivo — to bet on / commit to doing
Originally about gambling, apostar por has become a journalistic and corporate cliché meaning to commit to a course of action or to back an option.
La empresa apuesta por digitalizar todos sus servicios antes de 2030.
The company is committing to digitising all its services before 2030.
Apostamos por contratar a gente joven.
We're betting on hiring young people.
preocuparse por + infinitivo — to worry about doing
A verb where the por is the por of cause: to worry on account of. The infinitive describes what the worry is about.
No te preocupes por llegar tarde, te esperamos.
Don't worry about being late, we'll wait for you.
Mi madre se preocupa por todo: por que coma, por que duerma, por que estudie.
My mother worries about everything: about my eating, my sleeping, my studying.
(That last sentence shows the alternative por que + subjunctive when the subjects are different — useful to know but a separate topic.)
Other useful por verbs
- luchar por
- infinitivo — to fight to do. Lucha por ser feliz.
- votar por
- infinitivo — to vote in favour of doing. Votamos por aplazar la reunión.
- disculparse por
- infinitivo — to apologise for doing. Me disculpé por llegar tarde.
Luchó toda su vida por defender a los más vulnerables.
She fought all her life to defend the most vulnerable.
How English speakers go wrong here
The English preposition system maps onto Spanish in a way that looks helpful — dream about → soñar con? close enough — but it produces a steady drip of small errors that mark a learner as non-native. Three patterns dominate.
Pattern 1: defaulting to de
De is the workhorse infinitival preposition in Spanish (dejar de, acordarse de, tratar de, terminar de), so learners reach for it by reflex. Almost all con- and por-verbs get incorrectly produced with de at some point.
❌ Sueño de viajar a Japón.
Incorrect — must be 'con', not 'de'.
✅ Sueño con viajar a Japón.
I dream of travelling to Japan.
Pattern 2: translating the English preposition literally
English dream of feels closer to de than to con; English opt for feels closer to para than to por. Resist the urge to translate the preposition — memorise the Spanish unit.
❌ Optaron para no asistir.
Incorrect — 'optar' takes 'por', not 'para'.
✅ Optaron por no asistir.
They opted not to attend.
Pattern 3: confusing the meaning of acabar depending on its preposition
Acabar de + inf = to have just done. Acabar por + inf = to end up doing. Acabar con + noun = to put an end to. Three completely different meanings; the preposition is the whole signal.
❌ Acabé de irme sin cenar.
Incorrect — this means 'I had just left' before the speech act, not 'I ended up leaving'.
✅ Acabé por irme sin cenar.
I ended up leaving without dinner.
Common Mistakes
❌ Cuento de terminar el proyecto a tiempo.
Incorrect — 'contar' takes 'con', not 'de'.
✅ Cuento con terminar el proyecto a tiempo.
I'm counting on finishing the project on time.
❌ Me esfuerzo a aprender español.
Incorrect — 'esforzarse' takes 'por', not 'a'.
✅ Me esfuerzo por aprender español.
I'm making an effort to learn Spanish.
❌ El ladrón amenazó de matarlo.
Incorrect — 'amenazar' takes 'con', not 'de'.
✅ El ladrón amenazó con matarlo.
The thief threatened to kill him.
❌ Optamos para quedarnos en casa.
Incorrect — 'optar' takes 'por', not 'para'.
✅ Optamos por quedarnos en casa.
We chose to stay home.
❌ Empieza a leer las instrucciones primero.
Grammatically possible but means 'begin to read' as an action; for the 'first do this' sense, use 'por'.
✅ Empieza por leer las instrucciones primero.
Begin by reading the instructions first.
Key takeaways
- The con group centres on mental orientation toward a future or hypothetical action: soñar con, contar con, amenazar con, contentarse con.
- The por group centres on choice, effort, and the endpoint or starting point of a process: optar por, terminar por, empezar por, esforzarse por, apostar por, preocuparse por.
- These prepositions are not chosen by logic. Learn each verb together with its preposition as a single lexical unit.
- The contrast acabar de / acabar por / acabar con is the single most consequential preposition-driven meaning shift in this area — make sure all three feel automatic.
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Start learning Spanish→Related Topics
- 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.
- Infinitivo después de preposiciónA2 — The iron rule of Spanish syntax: any preposition is followed by the infinitive, never the gerund — antes de comer, sin pensar, para estudiar, después de llegar.
- La preposición 'con'A1 — The Spanish preposition 'con' covers accompaniment, instrument, and manner — and is the only preposition that fuses with pronouns to form 'conmigo', 'contigo', 'consigo'.
- Por para causa: '¿por qué?'A2 — Spanish 'por' answers 'why?' — it marks cause, motive, reason, and the agent of passive voice. It contrasts with 'para' (purpose / goal), and the difference between 'because of' and 'in order to' is one of the longest-running learner headaches in Spanish.