Numbers from 0 to 100

Up to fifteen, every number is its own word

The first sixteen numbers, from cero to quince, have to be learned one by one: nothing inside them repeats. After that, Spanish stops inventing words and starts combining the ones you already know, so the hard part of counting is over very quickly.

From 16 to 29: one glued word

16 to 19 are dieci + the unit: dieciséis, diecisiete, dieciocho, diecinueve. 20 is veinte, and 21 to 29 are veinti + the unit: veintiuno, veintidós, veintitrés, veinticuatro, veinticinco, veintiséis, veintisiete, veintiocho, veintinueve. Four of them carry a tilde (dieciséis, veintidós, veintitrés, veintiséis): the stress falls on the last syllable although the word ends in a vowel or s, exactly the exception you learned with café.

From 30 on: tens, then y, then the unit

From thirty onwards a number is three separate words: treinta y dos, cuarenta y ocho. The little y joins tens to units and appears nowhere else – never after cien, never inside veintidós. Exactly one hundred is cien: cien euros, cien personas.

Uno turns into un or una before a noun

On its own you count uno, but in front of a noun it behaves like the article: un libro, una casa. The same happens inside bigger numbers: veintiún años, treinta y un días, but veintiuna personas, cuarenta y una semanas. No other number changes its form.

Asking how many: ¿cuántos? ¿cuántas?, and saying your age

¿Cuántos? goes with masculine nouns and ¿cuántas? with feminine ones: ¿cuántos libros?, ¿cuántas sillas? Age in Spanish is something you have: tener + number + años. ¿Cuántos años tiene tu hermana? – Tiene treinta años. A phone number is read in small groups, often pairs: 612 34 56 → seis-doce, treinta y cuatro, cincuenta y seis.

¿Cuántos años tienes? – Tengo veinticinco años.How old are you? – I am twenty-five.

Mi número es el seis, quince, veintidós, treinta y tres.My number is six, fifteen, twenty-two, thirty-three.