While you may not think about it, numbers are adjectives too! Cardinal numbers are adjectives that answer the question, "How many?" They indicate a specific number of a noun but don’t have to match that noun in gender or number except for a few cases (uno, ciento).

  • Uno, dos, tres, cuatro, cinco. (One, two, three, four, five.)
  • Mi madre tiene seis hijos. (My mom has six kids.)
  • Ahora son las doce y veinte. (Right now it is twelve twenty.)

Basic Cardinal Number Forms 0-100

0 cero 15 quince
1 uno (un) / una 16 dieciséis
2 dos 17 diecisiete
3 tres 18 dieciocho
4 cuatro 19 diecinueve
5 cinco 20 veinte
6 seis 30 treinta
7 siete 40 cuarenta
8 ocho 50 cincuenta
9 nueve 60 sesenta
10 diez 70 setenta
11 once 80 ochenta
12 doce 90 noventa
13 trece 100 cien
14 catorce    

Cardinal numbers do not change according to gender or number except for uno and ciento and any derivatives of uno.
Uno is only used when counting. It changes to un in front of singular masculine nouns and una in front of singular feminine nouns.

  • un libro (one book)
  • una casa (one house)
  • veintiún mil (twenty-one thousand)
  • veintiuna manzanas (twenty-one apples)

Cien changes to ciento in numbers above 100 and changes according to the gender of the noun (cientos, cientas).

  • cien (one hundred)
  • ciento y uno (one hundred one)
  • Quiero trescientos libros. (I want three hundred books.)
  • Hay doscientas casas en este barrio. (There are two hundred houses in this neighborhood.)

Numbers 0-15 and multiples of 10

Numbers 0 through 15 and multiples of 10 (30, 40, 50, etc.) have unique forms that must be memorized.

Basic Cardinal Numbers 16-29

Numbers 16-29 use a combination of dieci or veinti (veinte with the final -e changed to an -i) and another number, condensed into one word. The singular word sounds very similar to the separate numbers when pronounced aloud (diez y seis sounds a lot like dieciséis).

16 dieciséis (diez y seis) 24 veinticuatro (veinte y cuatro)
17 diecisiete (diez y siete) 25 veinticinco (veinte y cinco)
18 dieciocho (diez y ocho) 26 veintiséis (veinte y seis)
19 diecinueve (diez y nueve) 27 veintisiete (veinte y siete)
21 veintiuno (veinte y uno)
28 veintiocho (veinte y ocho)
22 veintidós (veinte y dos) 29 veintinueve (veinte y nueve)
23 veintitrés (veinte y tres)    

* Notice that 21, 22, 23 and 24 carry a tilde to hold the word stress on the last syllable since they are apocopated to a shorter version.

Basic Cardinal Numbers 31-99

For numbers 31-99, the combination into one word is a bit simpler. Use the multiple of 10 + 1-9.

31 treinta y uno 56 cincuenta y seis
32 treinta y dos 67 sesenta y siete
33 treinta y tres 78 setenta y ocho
34 treinta y cuatro 89 ochenta y nueve
45 cuarenta y cinco 91 noventa y uno

When to Use Cardinal Numbers

1. To Count

  • uno, dos, tres, cuatro... (one, two, three, four...)
  • veintiuno, veintidós, veintitrés... (twenty-one, twenty-two, twenty-three...)

2. To Tell Time

Use a form of Ser, the feminine definite article, and an cardinal number to indicate the time of day.

  • Son las ocho. (It is eight o'clock.)
  • Es la una y diez. (It is one ten.)

3. To Indicate Dates

Use the masculine definite article el and a cardinal number to indicate the day of the month except for the 1st when you will use the ordinal number: el primero.

  • Hoy es el diecinueve de mayo. (Today is May 19th.)
  • El primero de enero es mi cumpleaños. (January 1st is my birthday.)

4. To Indicate Age

Conjugate Tener to the subject to indicate the number of years a person “has.”

  • Yo tengo veinticuatro años. (I am twenty-four years old.)
  • Mi hermana tiene treinta y nueve años. (My sister is thirty-nine years old.)

Extra Note on Punctuation

To express decimals in Spanish, use a comma; and to express commas, use a decimal.

  • $1.694,68 (one thousand six hundred ninety-four dollars and sixty eight cents/mil seiscientos noventa y cuatro dólares y sesenta y ocho centavos)
  • Tenemos 13.000 votos. (We have thirteen thousand votes./Tenemos trece mil votos.)


Take a practice quiz! Take a Practice Quiz

Test what you know with our quiz tool. Click the image to get started (it's free!).

Category: adjectives | Keywords: