Spanish ordinal numbers: primero to décimo and how to use them

Spanish ordinal numbers tell you the position of something in a sequence — first, second, third — and the everyday set runs from primero (1st) to décimo (10th). Unlike English ordinals, which never change, Spanish ordinals behave like adjectives: they agree in gender and number with the noun they describe, so you say el primer día but la primera vez.

Two of them, primero and tercero, drop their final -o before a masculine singular noun, giving primer and tercer. Beyond tenth, Spanish speakers usually stop using ordinals and switch to ordinary counting numbers instead. The list below gives all ten with an example, and the sections explain agreement, the shortening, placement and when to drop ordinals altogether.

How ordinals agree with the noun

A Spanish ordinal is an adjective, so it copies the gender and number of the noun it goes with. That gives each ordinal four possible endings: -o, -a, -os, -as. Primero becomes primera, primeros, primeras; cuarto becomes cuarta, cuartos, cuartas, and so on. English has none of this — “first” is “first” whatever follows it — so the agreement is the main thing to get right.

Es mi primera clase de español.
It’s my first Spanish class.

Los primeros días son los más difíciles.
The first days are the hardest.

In practice you meet ordinals most often in the singular, describing a floor, a row, a chapter, a time or a place in a race. Because the noun’s gender decides the ending, learning the noun with its article (el piso, la planta) makes the ordinal choose itself.

Primero and tercero: the short forms

Primero and tercero are special: right before a masculine singular noun they drop the final -o and become primer and tercer. This shortening is called apocope, and it happens only in that one position.

Vivo en el primer piso, y mi tía en el tercer piso.
I live on the first floor, and my aunt on the third floor.

The full forms come straight back as soon as the noun is feminine, plural, or when the ordinal stands alone. So it is la primera vez (feminine), los primeros años (plural) and Llegué primero (standing alone), never primer in any of those. No other ordinal in the list shortens this way — segundo, cuarto and the rest keep their full form everywhere.

Fue el tercer intento, pero la tercera fue la vencida.
It was the third attempt, but the third time was the charm.

Where the ordinal goes

Ordinals normally sit before the noun, just like in English: el primer premio (the first prize), la segunda puerta (the second door). This is the default and the safest choice for a learner.

There is one very common exception worth knowing: with kings, popes and centuries, the ordinal comes after the name, and only up to tenth. Carlos I is read Carlos primero, Isabel II is Isabel segunda, and el siglo X is el siglo décimo. From eleventh onward even these switch to cardinal numbers, which leads neatly into the next point.

Felipe II fue un rey muy poderoso.
Philip the Second was a very powerful king.

When Spanish drops ordinals

This is the difference that surprises English speakers most. In English we happily say “the twenty-first floor” or “the fortieth anniversary”. Spanish speakers, by contrast, rarely use ordinals above tenth in everyday speech; they replace them with ordinary cardinal numbers.

So “the fifteenth floor” is usually el piso quince (literally “floor fifteen”), not el decimoquinto piso. “The twentieth century” is el siglo veinte, and a building’s “twenty-second floor” is la planta veintidós. The higher ordinals (undécimo, duodécimo, decimotercero…) do exist and appear in formal or legal writing, but you do not need them to speak naturally. For dates the same logic applies: only the first of the month is ordinal — el primero de mayo in much of Latin America, though Spain often says el uno de mayo — and every other day uses a cardinal: el dos de mayo, el quince de junio.

Trabajo en el piso veinte, no en el vigésimo piso.
I work on the twentieth floor, not on “the twentieth floor” (with the ordinal).

Knowing this saves you from the very formal, slightly bookish sound that piling up high ordinals produces. Stick to primero–décimo as adjectives, and count with cardinals above that.

Writing ordinals as figures

Spanish writes ordinals with a raised letter after the number: 1.º and 1.ª (first, masculine and feminine), 2.º, 3.er for the shortened tercer, and so on. You will see these on floors in a lift, in lists and in addresses. When you read them aloud, you say the full word: 3.er piso is tercer piso. This is only a spelling convention, so if the raised letters are hard to type, writing the word out is always correct.

Common mistakes

Not making the ordinal agree

Because English ordinals never change, learners often leave the Spanish one in its dictionary -o form. But it must match the noun.

la primero vez → la primera vez
the first time

Forgetting to shorten primero and tercero

Before a masculine singular noun, primero and tercero lose the -o. Keeping it sounds wrong to native ears.

el primero día → el primer día
the first day

Using ordinals for high numbers

Above tenth, everyday Spanish uses cardinals. The long ordinal forms sound stilted in speech.

el vigésimo quinto aniversario → el aniversario veinticinco
the twenty-fifth anniversary

Ordinals are one of those small systems that pay off quickly: ten words, one agreement rule and one shortening cover almost everything you need for floors, dates, rankings and directions. In Fluera you meet primero, segundo and tercero inside real sentences with audio, so the agreement becomes a habit rather than a chart. Put them to work when you practice Spanish.

Practice