The Twenties (21 to 29)
In Spanish, numbers from 21 to 29 are written as a single word. To form them, take veinte (twenty), change the final -e to -i-, and attach the single digit.
| Number | Spanish |
|---|
| 21 | veintiuno |
| 22 | veintidós |
| 23 | veintitrés |
Notice that veintidós, veintitrés, and veintiséis gain a written accent mark to keep the stress on the correct syllable.
Just like the number one, veintiuno changes its form depending on how you use it. When it comes directly before a masculine noun, it drops the final -o and adds an accent mark, becoming veintiún. When counting or pointing to a number (like a page number), it stays veintiuno.
Numbers 31 to 99
For numbers 31 and above, the pattern changes. Instead of combining everything into one word, you will use three separate words: the tens, the word y (and), and the ones.
| Number | Spanish |
|---|
| 31 | treinta y uno |
| 45 | cuarenta y cinco |
| 99 | noventa y nueve |
These numbers work exactly like the smaller ones you already know. You can use them to describe nouns, talk about prices, or state ages.