ORDINAL NUMBERS
| primero | - | first |
| segundo | - | second |
| tercero | - | third |
| cuarto | - | fourth |
| quinto | - | fifth |
| sexto | - | sixth |
| séptimo | - | seventh |
| octavo | - | eighth |
| noveno or nono | - | ninth |
| décimo | - | tenth |
| undécimo | - | eleventh |
| duodécimo | - | twelfth |
| decimotercio or decimotercero | - | thirteenth |
| decimocuarto | - | fourteenth |
| decimoquinto | - | fifteenth |
| decimosexto | - | sixteenth |
| decimoséptimo | - | seventeenth |
| decimoctavo | - | eighteenth |
| decimonoveno or decimomono | - | ninteenth |
| vigésimo | - | twentieth |
| vigésimo prim(er)o | - | twenty-first |
| vigésimo segundo | - | twenty-second |
| trigésimo | - | thirtieth |
| cuadragésimo | - | fortieth |
| quincuagésimo | - | fiftieth |
| sexagésimo | - | sixtieth |
| septuagésimo | - | seventieth |
| octogésimo | - | eightieth |
| nonagésimo | - | ninetieth |
| centésimo | - | hundreth |
| centésimo prim(er)o | - | hundreth and first |
| centésimo segundo | - | hundreth and second |
| ducentésimo | - | two hundreth |
| tricentésimo | - | three hundreth |
| cuadringentésimo | - | four hundreth |
| quingentésimo | - | five hundreth |
| sexcentésimo | - | six hundreth |
| septingentésimo | - | seven hundreth |
| octingentésimo | - | eight hundreth |
| noningentésimo | - | nine hundreth |
| miléimo | - | thousandth |
| dos milésimo | - | two thousandth |
| doscientos milésimo | - | two hundred thousandth |
| millonésimo | - | millionth |
| dos millonésimo | - | two millionth |
Things to note:
In most cases you can use the cardinal number in place of the ordinal numbers above tenth
(décimo).
The ordinals primero (first) and tercero (third) drop the final "o" before a masculine singular noun.
el primer presidente - the first president
el tercer ejemplar - the third copy
The numbers can be abbreviated by using the last syllable or the last letter of the number to the written number. The ending must agree with the gender of the noun.
El 1ro hombre - the first (or 1st) man
El 1o hombre - the first (or 1st) man
La 2da lección - the second (or 2nd) lesson
La 2a lección - the second (or 2nd) lessonNote that lesson is "la lección". As such the word for second would be segunda not segundo.
Ordinal numbers may be placed before or after the nound.
el primer día = the first day
el día primer = the first day
Note: if you use a cardinal number in place of an ordinal number it usually follows the noun:
el día diecisiete = the seventeenth day
In address where a floor number is given it is generally expressed as the number followed by a "o".
4o = the fourth floor
For royalty and popes ordinal numbers are used only through décimo (10th). The definite article "the" (el) is omitted and "nono" replaces "noveno".
| Carlos Quinto | = | Charles V or Charles the Fifth |
| Alfonso Trece | = | Alfonso XIII or Alfonso the Thirteenth |
| Pío Nono | = | (Pope) Pius IX or (Pope) Pius the Nineth |