The same preposition that marks the endpoint of motion (voy a Madrid) also marks the moment on the clock when something happens. La reunión empieza a las nueve. Quedamos a las ocho de la tarde. Te llamo a mediodía. The metaphor is the same — a points to an endpoint, here a point in time rather than a point in space — but the temporal use deserves its own page because Spanish carves up time differently from English, and the distribution between a, en, and por is not what English speakers expect.
The core pattern: a + clock time
When you want to say something happens at a specific clock time, Spanish uses a + las + hour.
La clase empieza a las nueve de la mañana.
Class starts at nine in the morning.
Cenamos a las diez los fines de semana.
We have dinner at ten on weekends.
El tren sale a las seis y veinte.
The train leaves at six twenty.
¿A qué hora quedamos mañana?
What time shall we meet tomorrow?
Three things to notice. First, the definite article is obligatory before the hour: a las nueve, never ❌a nueve. Second, the article is plural for every hour except one — because clocks were originally read as las (horas), plural. Third, the interrogative is ¿a qué hora?, not ❌¿en qué hora? or ❌¿a qué tiempo?
The one-o'clock exception
There is exactly one singular hour in Spanish: la una. Everything else is plural.
Quedamos a la una en la puerta del bar.
Let's meet at one at the door of the bar.
Salgo del trabajo a la una y media.
I get off work at half past one.
Compare with the plural forms for all other hours:
Empezamos a las dos en punto.
We start at two o'clock sharp.
La película termina a las once.
The film ends at eleven.
This singular/plural split mirrors how Spanish thinks about the clock: ¿qué hora es? — es la una (singular) but son las dos (plural). When you ask the time, the verb agrees with how many hours there are. The preposition a preserves this same agreement.
Building out the clock: y media, y cuarto, menos cuarto
Spanish reads the minutes additively or subtractively, depending on whether you have passed the half-hour mark.
| Spanish | English |
|---|---|
| a las tres en punto | at three o'clock sharp |
| a las tres y cuarto | at quarter past three |
| a las tres y media | at half past three |
| a las cuatro menos cuarto | at quarter to four |
| a las cuatro menos diez | at ten to four |
| a las tres y veinticinco | at three twenty-five |
In peninsular Spanish, the menos construction (las cuatro menos cuarto) is universal. You will not hear para las cuatro / faltan cuarto para las cuatro in Spain — that's Latin American. Stick with menos on this side of the Atlantic.
La reunión es a las diez menos cuarto, no te retrases.
The meeting is at quarter to ten, don't be late.
Parts of the day, named hours
A small set of fixed temporal nouns also take a, without an article: a mediodía, a medianoche, al amanecer, al atardecer, al anochecer. Notice the contraction a + el = al in the last three, because amanecer, atardecer, anochecer are masculine nouns referring to specific moments.
Quedamos a mediodía en la plaza.
Let's meet at noon in the square.
Llegamos a medianoche, agotados pero contentos.
We arrived at midnight, exhausted but happy.
Al amanecer ya estábamos en la cumbre.
By daybreak we were already at the summit.
Al atardecer el cielo se puso rojo.
At sunset the sky turned red.
These named times of day are treated like clock times — single points on the timeline — and so they take a in the same way a las tres does.
The three temporal prepositions: a, en, por
Spanish distributes time across three prepositions, each handling a different granularity. Get this distribution wrong and your sentence will sound foreign even if every individual word is correct.
| Preposition | Used for | Example |
|---|---|---|
| a | clock times, named moments | a las tres, a mediodía |
| en | months, years, seasons, centuries | en mayo, en 2025, en verano |
| por | parts of the day (general) | por la mañana, por la tarde, por la noche |
Trabajo por la mañana y estudio por la tarde.
I work in the morning and study in the afternoon.
Salgo del gimnasio a las ocho de la mañana.
I leave the gym at eight in the morning.
En enero de 2025 me mudé a Valencia.
In January 2025 I moved to Valencia.
Crucial contrast: por la mañana (general, "in the morning") vs a las ocho de la mañana (specific, "at eight AM"). When you say a las ocho de la mañana, the de la mañana part is the same construction the English "AM/PM" disambiguates. It is not por la mañana — that means "in the morning" in a general, no-clock-time sense.
A pitfall worth flagging
English speakers often combine en with a clock time because "in" sounds like en. ❌En las tres de la tarde is wrong. The correct form is a las tres de la tarde. The en of en mayo and the en of ❌en las tres are not the same — only the first one is valid Spanish. Clock times are always a.
Al + infinitive: "upon X-ing"
A specialized temporal construction worth knowing from day one of A1: al + infinitive means "upon doing X" or "when X happens." It packages a temporal clause into a single phrase.
Al llegar a casa, me di cuenta de que había olvidado el móvil.
Upon getting home, I realized I had forgotten my phone.
Al verla, sonrió y se acercó.
On seeing her, he smiled and came over.
Al salir del cine empezó a llover.
As we came out of the cinema, it started to rain.
This al + infinitive construction is everywhere in spoken peninsular Spanish. It replaces longer subordinate clauses (cuando llegué a casa → al llegar a casa) and gives the sentence a tighter, more elegant feel. The implied subject is whatever subject the main clause has. Same subject across both clauses — that is the only requirement.
Frequency expressions with a
A specialized but extremely common use: stating how often something happens per time unit. Spanish uses a between the number and the time period.
Voy al gimnasio tres veces a la semana.
I go to the gym three times a week.
Me lavo los dientes dos veces al día.
I brush my teeth twice a day.
Vamos a Asturias una vez al año, en agosto.
We go to Asturias once a year, in August.
La revista sale una vez al mes.
The magazine comes out once a month.
Notice the article: a la semana, al día, al mes, al año. The pattern is número + veces + a + el/la + tiempo. English uses bare "a week / a day / a year" without a preposition; Spanish needs both the preposition and the article.
Asking the time vs telling the time vs scheduling
Three related but distinct constructions, all involving the clock:
| Question | Construction | Example |
|---|---|---|
| What time is it? | verb ser | Son las tres. |
| What time does X happen? | a + las + hora | La clase es a las tres. |
| When did you arrive? | a + las + hora | Llegué a las cinco. |
¿Qué hora es? — Son las cinco y media.
What time is it? — It's half past five.
¿A qué hora es la cena? — A las nueve.
What time is dinner? — At nine.
¿A qué hora llegaste anoche?
What time did you get in last night?
Notice that ser is used for telling the time (son las cinco), while a introduces the time when something happens. The two questions look similar in English but use different structures in Spanish.
Common Mistakes
❌ La reunión empieza en las nueve.
Wrong — clock times take 'a', never 'en'.
✅ La reunión empieza a las nueve.
The meeting starts at nine.
❌ Quedamos a tres.
Wrong — Spanish requires the article 'las' (or 'la' for one o'clock) before the hour.
✅ Quedamos a las tres.
Let's meet at three.
❌ Trabajo a la mañana.
Wrong — general parts of the day take 'por', not 'a'. Use 'a' only with a specific clock time.
✅ Trabajo por la mañana.
I work in the morning.
❌ Voy al gimnasio tres veces en la semana.
Wrong — frequency expressions take 'a + el/la', not 'en'.
✅ Voy al gimnasio tres veces a la semana.
I go to the gym three times a week.
❌ Quedamos a la una y treinta.
Awkward — Spanish prefers 'y media' for half-past.
✅ Quedamos a la una y media.
Let's meet at half past one.
Key takeaways
- Clock times take a: a las tres, a la una, a mediodía. The article (la for one, las for everything else) is obligatory.
- Distinguish carefully among the three temporal prepositions: a (clock times), en (months, years, seasons), por (general parts of the day).
- Por la mañana = "in the morning" (general); a las ocho de la mañana = "at 8 AM" (specific). Do not conflate them.
- Al + infinitive compresses a "when X happens" clause into a single phrase — one of the most useful constructions in Spanish.
- Frequency expressions use a + article + time unit: tres veces a la semana, dos veces al año.
- Peninsular Spanish reads minutes past the half hour with menos: las cuatro menos cuarto, never para las cuatro (which is Latin American).
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Start learning Spanish→Related Topics
- Preposiciones: panorama generalA1 — An overview of the Spanish preposition inventory, their core meanings, and the fundamental rule that prepositions never map one-to-one to English.
- A para direcciónA1 — The preposition a marks the endpoint of motion in Spanish — destination, target, the place you are heading. Contrast with en (location) and learn the peninsular preference for entrar en over entrar a.
- A personal: con objetos directos humanosA2 — The personal a is the small word that marks a human direct object in Spanish. Mandatory before specific people and personalized animals, optional or absent before non-specific humans. One of the great learner traps.
- Expresiones de tiempoA1 — The peninsular toolkit for talking about when: ahora, ahora mismo, ayer, hoy, mañana, esta mañana, anoche, dentro de un rato, hace una semana. Includes the peninsular meal schedule, the menos cuarto vs cuarto para distinction, and the perfecto-vs-pretérito rule that ties tense to time expressions.
- Cómo elegir entre por y paraA2 — The canonical Spanish preposition decision. POR points backwards (cause, exchange, route, duration, agent). PARA points forwards (purpose, destination, deadline, recipient, opinion). Memory device, every common use organised by category, peninsular Spanish's distinctive a por construction, and the minimal pairs that train the instinct.