Cardinal Numbers 0–30 | Spanish (Latin America) Grammar

Cardinal numbers are the building blocks for counting, telling prices, giving ages, and expressing quantities. The numbers from 0 to 30 in Spanish include a handful of spelling quirks worth memorizing early, because they show up in nearly every conversation.

The numbers 0 to 15

The first fifteen numbers each have their own unique form. There are no shortcuts here — you simply need to learn them.

Number	Spanish	Number	Spanish
0	cero	8	ocho
1	uno	9	nueve
2	dos	10	diez
3	tres	11	once
4	cuatro	12	doce
5	cinco	13	trece
6	seis	14	catorce
7	siete	15	quince

Tengo tres hermanos y dos hermanas.

I have three brothers and two sisters.

Hay quince estudiantes en la clase.

There are fifteen students in the class.

The numbers 16 to 19

Starting at sixteen, Spanish forms numbers by combining diez (ten) with the digit. In modern Latin American Spanish these are written as a single word, not as three words.

Number	Spanish	Literal meaning
16	dieciséis	ten and six
17	diecisiete	ten and seven
18	dieciocho	ten and eight
19	diecinueve	ten and nine

Notice the accent on dieciséis — it is the only one of the four that needs one. The older three-word spelling (diez y seis) is no longer recommended.

Mi hermana tiene dieciséis años.

My sister is sixteen years old.

Twenty and the 21–29 range

The number 20 is veinte. From 21 to 29, Spanish again writes each number as a single word, this time built on veinti-.

Number	Spanish	Number	Spanish
20	veinte	25	veinticinco
21	veintiuno	26	veintiséis
22	veintidós	27	veintisiete
23	veintitrés	28	veintiocho
24	veinticuatro	29	veintinueve

Pay attention to the written accents on veintidós, veintitrés, and veintiséis. These marks are required — leaving them out is a spelling error, not a stylistic choice.

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The 16–29 one-word rule is unique: from 31 onward, numbers go back to being written as three words (treinta y uno, cuarenta y dos). See Cardinal Numbers 31–100.

Thirty

The number 30 is treinta. Don't confuse the spelling with trienta — the e comes before the i.

Hay treinta días en abril.

There are thirty days in April.

The shortening of uno

When uno appears directly before a masculine singular noun, it drops the final -o and becomes un. Before a feminine noun, it becomes una. This applies to any number ending in uno, including veintiuno.

Form	Use	Example
uno	counting, standing alone	uno, dos, tres
un	before masculine noun	un libro
una	before feminine noun	una mesa

Veintiún estudiantes llegaron tarde.

Twenty-one students arrived late.

Compré veintiuna manzanas en el mercado.

I bought twenty-one apples at the market.

Notice that veintiún carries a written accent when it shortens — the stress stays on the final syllable. The feminine form veintiuna keeps its a and does not need an accent.

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When just answering "how many?" with a number, use the full form: ¿Cuántos tienes? — Uno. The shortening only happens when the number is immediately followed by the noun it counts.

Practical uses

These small numbers cover most everyday situations — ages, phone digits, small quantities, and basic counting. Practice them out loud until they feel automatic before moving on.

Mi número de teléfono termina en cero, cuatro, siete.

My phone number ends in zero, four, seven.

Tengo veintitrés años y mi hermano tiene veintiocho.

I am twenty-three years old and my brother is twenty-eight.

Common mistakes to avoid

A few errors come up again and again for beginners. Watch out for these:

Dropping the accents. Dieciseis, veintidos, and veintitres without their marks are misspellings, not shortcuts. The written accent is part of the word.
Writing 16–29 as three words. Forms like diez y seis or veinte y dos are considered outdated. Always write them as one word in modern Latin American Spanish.
Forgetting to shorten uno before nouns. Tengo uno libro is wrong; it should be tengo un libro. The shortening isn't optional.
Adding a written accent to veintiuna. Only the masculine short form veintiún needs one — veintiuna doesn't.

Veintiún años y veintiuna semanas de experiencia.

Twenty-one years and twenty-one weeks of experience.

Once you're comfortable with 0–30, the jump to higher numbers is mostly about learning the round tens. Continue with Cardinal Numbers 31–100. For more on how uno and other words drop endings before nouns, see shortened forms.