Using Ordinal Numbers in Spanish

If you want to say first in Spanish, theres a word for that — and its nothing like uno, the word for one. Its primero, the first of what are called the ordinal numbers. Ordinal Numbers Function as Adjectives The ordinal numbers might be thought of as the adjective form of the cardinal numbers, the numbers in the form they are most often used. Thus uno (one) is a cardinal number, while primero (first) is its ordinal form. The same goes for the cardinal dos  (two) and the ordinal segundo (second). In Spanish, the ordinal forms are used most commonly for the numbers 10 and under. They are: First: primeroSecond: segundoThird: terceroFourth: cuartoFifth: quintoSixth: sextoSeventh: sà ©ptimo, sà ©timoEighth: octavoNinth: novenoTenth: dà ©cimo When used as an adjective, ordinal numbers must agree with the nouns they refer to in both number and gender: el segundo coche (the second car, where coche is masculine), but la segunda vez (the second time, where vez is feminine). Note also that when primero and tercero precede a singular masculine noun, the final -o is dropped: el primer rey (the first king), el tercer trimestre (the third trimester). This change is known as apocopation. For larger numbers, it is common to use simply the cardinal number, especially in speech. Thus el siglo veinte (the 20th century) is more common than the cardinal form, el siglo vigà ©simo, and in writing the numerical (el siglo 20) or Roman (el siglo XX) form is often used. It is also common to word a sentence in such a way that the ordinal form is not used. So, for example, cumple cuarenta y cinco aà ±os (literally, she reaches 45 years) would be the most common way of saying it is someones 45th birthday. In general, the ordinal numbers for 11th and above can be considered mostly a formal usage. In any case, here are examples of larger ordinal numbers. 11th: undà ©cimo12th: duodà ©cimo13th: decimotercero14th: decimocuarto15th: decimoquinto16th: decimosexto17th: decimosà ©ptimo18th: decimoctavo19th: decimonoveno20th: vigà ©simo21st: vigà ©simo primero22nd: vigà ©simo segundo23rd: vigà ©simo tercero24th: vigà ©simo cuarto30th: trigà ©simo31st: trigà ©simo primero32nd: trigà ©simo segundo40th: cuadragà ©simo50th: quincuagà ©simo60th: sexagà ©simo70th: septuagà ©simo80th: octogà ©simo90th: nonagà ©simo100th: centà ©simo200th: ducentà ©simo300th: tricentà ©simo400th: cuadringentà ©simo500th: quingentà ©simo600th: sexcentà ©simo700th: septingentà ©simo800th: octingà ©simo900th: noningentà ©simo1,000th: milà ©simo2,000th: dosmilà ©simo3,000th: tresmilà ©simo4,000th: cuatromilà ©simo1,000,000,000th: millonà ©simo Ordinal numbers can also be written using a superscripted o or a depending on whether it is masculine or feminine, respectively. For example, the equivalent of 2nd is 2o when referring to a masculine noun and 2a when referring to a feminine one. The lower-case  superscripted o should not be confused with the symbol for degrees. Using ordinary lower-case letters (as in 2nd) is also possible when supercripts arent available: 2o, 2a. Mnemonic Device: Remembering the Ordinals You may be able to help youself remember the ordinal forms by connecting them with English words you already know: Primero is related to primary.Segundo is similar to second.Tercero is related to tertiary.A quarter, similar to cuarto, is a fourth of a whole.Five children born together are quintuplets, using the same root word as quinto.An octave, similar to octavo, has eight notes.The decimal, similar to dà ©cimo, system is based on the number 10. Sample Sentences Showing Use of Ordinal Numbers El primer dà ­a fuimos amenazados por un grupo de manifestantes. (The first day we were threatened by a group of protesters.) La estrella de muchas pelà ­culas ha adoptado una segunda nià ±a. (The star of many films has adopted a second girl.) La Fà ³rmula 1 contempla seriamente la opcià ³n de un tercer coche por equipo. (Formula 1 is seriously considering the option of a third team car.) Hermine, la octava tormenta tropical de la temporada de huracanes en el Atlà ¡ntico, se formà ³ hoy. (Hermine, the eighth tropical storm of the hurricane season, formed in the Atlantic today.) Puebla se ubica en el dà ©cimo lugar de las ciudades mà ¡s caras del paà ­s. (Pueblo occupies 10th place of the countrys most expensive cities.) Esta es la lista de episodios pertenecientes a la decimosexta temporada. (This is the list of episodes from the 16th season.) El empresario es el centà ©simo hombre mà ¡s rico de Canadà ¡. (The businessman is the 100th richest man in Canada.) Eres la  milà ©sima  persona que me dice que estoy muy guapo.  (You are the  1,000th  person to tell me that I am very handsome.)