The Spanish language has two names: () and (). Spanish speakers from different countries or backgrounds can show a preference for one term or the other, or use them indiscriminately, but political issues or common usage might lead speakers to prefer one term over the other. This article identifies the differences between those terms, the countries or backgrounds that show a preference for one or the other, and the implications the choice of words might have for a native Spanish speaker.

Today, the national language of Spain – the official Spanish language – is Spanish (as opposed to the regional languages of Spain, such as Galician, Catalan, Asturleonese, and Basque). Generally speaking, both terms (español and castellano) can be used to refer to the Spanish language as a whole, with a preference for one over the other that depends on the context or the speaker's origin. Castellano (as well as Castilian in English) has another, more restricted, meaning, relating either to the old Romance language spoken in the Kingdom of Castile in the Middle Ages, predecessor of the modern Spanish language, or to some formal varieties of Spanish which are popularly imagined as related to the historical region of Castile, in central Spain.

History of the terms

Originally Castilian (castellano) referred to the language of the Kingdom of Castile, one of several northern kingdoms that spread across the Iberian Peninsula through the Middle Ages, from about the 8th to the 15th centuries. Traditionally the first recorded examples of written Castilian/Spanish are considered to be the Glosas Emilianenses, a number of isolated words added to a Latin text as an aid to the reader, dated to the eleventh century. Soon after that there begin to appear discursive texts in Castilian, such as the Cantar de Mio Cid. This early Romance language was derived from Latin and evolved into modern Spanish.

However, the term Spanish (español) is a more recent term that first referred to Spain as a country, and then to the predominant language spoken in that country. Spain as a truly unified nation appeared centuries later than the language and the Kingdom of Castile; in fact, it was only in the late 15th century that the personal union between the Crowns of Castile and Aragon unified Spain. The actual legal unification date is disputed, but commonly agreed to have occurred not earlier than the eighteenth century at the end of the War of the Spanish Succession. Only then did the Castilian language begin to be commonly called Spanish.

In 1492, the arrival of Christopher Columbus on a Castilian-paid expedition paved the way for the Spanish colonization of the Americas. As a result of this process, most countries in South America now speak the same language as Castile. Until about the eighteenth century, the Kingdom of Castile, and not Spain as a whole, was the colonizing power, and the language used was called castellano. Thus, some Hispanic American countries formerly under Spanish rule have retained the custom of calling it castellano, while others eventually switched to calling it español, with many different factors influencing the final choice.

In English, the term Spanish relates both to the language and to the nation. The noun used for a person from Spain is Spaniard, with the collective noun the Spanish. The term Castilian is much less widespread among English speakers than the term Spanish.

Español Two main hypotheses have been proposed for the origin of the word español: one based on dissimilation in Old Spanish españón (from a presumed Vulgar Latin *hispaniōne), and the other on an Occitan term derived from a presumed Vulgar Latin *hispaniolus. Both Latin ancestor words are based on the place name Hispania (which evolved into España by regular sound changes); and both are marked with an asterisk to indicate that they are reconstructed, not directly attested.

The dissimilation hypothesis, advanced by Ramón Menéndez Pidal,Manual de gramática histórica española (1904/1980), p. 181 (§66.2). presumes that Latin Hispania was lengthened by the derivational suffix -ōne (which survives in other ethnonyms such as bretón, borgoñón, sajón, and lapón). The Old Spanish form españon is documented in works of the 13th and 14th centuries.For example the Poema de Fernán González and the Libro del cauallero Zifar. It is suggested that the final /n/ of this form changed to /l/ by dissimilation from the previous nasal consonant, ñ. This sporadic sound change is observed in some other words: Menéndez Pidal cites Barcelona (from Barcinone) and delante (from de in ante); Lathrop adds ingle (from ing[ui]ne) and sangre (from sang[ui]ne).Thomas A. Lathrop, The Evolution of Spanish (Newark, Del.: Juan de la Cuesta), p. 97.

According to the Occitan scenario, advanced by Rafael Lapesa,Historia de la lengua española (Madrid: Gredos, 1981), p. 199 (§51.3). the Spanish borrowed the Occitan name for themselves, which was the name España plus the diminutive suffix -ol, from the Latin -olus. The Occitan influence is inferred because in Castilian the same Latin suffix would have produced *españuelo rather than español. Lapesa counters the dissimilation hypothesis by citing other words with -ñón in which dissimilation did not take place: cañón, borgoñón, riñón, etc.P. 200, note 8. (However, the suffix could have been restored analogically in these, or they were formed after the dissimilation took place.) Penny, in discussing loans from French and Occitan, calls this "the most remarkable loan of all, español 'Spanish', replacing native españón."Ralph Penny, A History of the Spanish Language (Cambridge University Press, 1991), p. 225.

The name Hispania was applied to the Iberian Peninsula by the Romans when they discovered and later subjugated it. One theory about this name is that it comes from Canaanite אי שפנים (ʾî šəpānîm), meaning 'island of hyraxes', named by Canaanite-speaking Phoenicians who mistook Spain's large rabbit population for hyraxes.Today the Spanish population of wild rabbits is much less abundant than in ancient times, due to the introduction of the myxomatosis virus to mainland Europe in the 1950s. Several other theories about the name have been advanced as well (see Hispania).

The Romans called the inhabitants of Hispania hispani (singular: hispanus), and the relevant adjective was hispanicus. These terms, had they undergone regular sound change into Castilian, would have developed into España, *espanos (singular: *espano) and *espánego or *espango—but in reality, only the first term exists in modern Castilian.

As the branches of Vulgar Latin began to evolve into separate Romance languages, the term that would evolve into español began to be used to refer to these derivative languages (especially as opposed to the Arabic and Hebrew of the Moorish and Jewish inhabitants of Iberia). It was at first a general term that embraced the various dialects of Iberian Romance spoken in the area, including the forebears of modern Portuguese, Galician, Castilian and Catalan. However, with the rise of Castile as a power, and its absorption of all surrounding regions into an ever-growing empire that eventually spread to the New World, the term España was eventually equated with the peninsular territories ruled by the Crown. With this, the break with the Roman concept of Hispania was complete, and the term acquired its modern meaning of 'all of Iberia except for Portugal and Andorra'. Similarly, español came to be used to refer to the common language of this new country: Castilian.

The terms España and español spread to other languages. The English name Spain is from the French Espagne. Spanish is Spain plus the English suffix -ish. The term continues evolving as other languages adapt these words to form their own name for Spain—for example, Japanese スペイン語 (Supein-go), 'Spanish language', and スペイン人 (Supein-jin), 'Spaniard', derive from the Japanese word for Spain, スペイン (Supein), which, in turn, derives from English Spain. In Chinese, the word is taken directly from Spanish (or perhaps even Latin) rather than English: 西班牙 (Pinyin phonetic symbols: xībānyá) for Spain and 西班牙语 (Pinyin: xībānyá yǔ), or the abbreviation 西語 (Pinyin: xī yǔ) for the Spanish language. The Arabic إسبانية (isbāniya) for Spain derives directly from the word Hispania (noting that the absence of "p" in the Arabic alphabet makes it a "b").

("Castile" in English) is commonly thought to mean 'Castle-land'. The word is derived from Latin , the plural of , which, in turn, is a diminutive form of ' 'fortress, castle'. Through most of the Middle Ages the word was spelled , a form that survives in Leonese today. (Modern Spanish has transformed all words ending in , into , .) The adjective derived from is . also means 'castellan', i.e. a castle master. There is a comic scene based on the play on words Castilian/castellan in the novel Don Quixote (Chapter 2).

The region was thus named because it was a frontier land controlled from a series of fortified castles. It shared borders with rival Moorish Iberia (to the south) and the Christian kingdoms of Leon (to the west) and Navarre and Aragon (to the east).

In Guatemala, although Spanish is the official language, the Maya peoples, descendants of the original inhabitants of the region, call it la castilla, keeping the original name from colonial times. Mayans speak at least 22 different Mayan languages and dialects, including Mam, Pocomam, Kaqchikel, Tz’utujil, Q’eqchi’, and Kʼicheʼ.

Other local names "Cristiano" During the presence of Moors in Hispania, Spanish was sometimes given the name cristiano ("Christian") to distinguish it from the Arabic and Hebrew languages - although the language spoken by Christians under Islamic rule was Mozarabic (of which Aragonese is actually the closest living language). The expression Hablar en cristiano () means to talk in a plain, understandable way. Sometimes it was addressed aggressively at people speaking other languages of Spain, such as Catalan or Basque, to the chagrin of the speakers of these languages. The phrase is not used outside Spain.

"Language of Cervantes" The term as an epithet for the Spanish language began to be used early in the 19th century. Mariano José de Larra uses the expression in his essay , first published in 1823.Obras completas , Vol. 4 (Madrid: José M. Repullés, 1837), p. 66. In 1829 it appears in , by Manuel Sivela.Paris: Gaultier-Laguionie, p. 185. Soon after that it appears in an anonymous article in the ."De las traducciones", No. 64 (May 29, 1832), p. 264. The poet Nicasio Camilo Jover, in his poem , states directly Glorias de España: Poesías históricas (Madrid: D.F.A. Fernel, 1848), p. 227 Spanish is called in a book published in 1830,Rafael Díaz Arenas, Memorias históricas y estadísticas de Filipinas y particularmente de la grande isla de Luzón (Manila: Diario de Manila) and in another one published in 1838."El Tío Cigüeña" (pseud. of Juan Mieg), Cuatro palabras á los señores traductores y editores de novelas (Madrid: Hijos de Doña Catalina Piñuela), p. 67.

Occasionally the term refers to the language of Spanish Golden Age literature generally, rather than simply to that of Cervantes.For example Héctor M. Ardila A. and Inés Vizcaíno G., Hombres y mujeres en las letras colombianas (Bogotá: Magisterio, 2008), p. 14: "La lengua clásica, la lengua de Cervantes y Fray Luis de León".

"The language of Cervantes" in English—as a term for the Spanish language generally—comes into use in the 1840s. Examples appear in Janin (1841)Jules Janin, "Biographical Notice of Le Sage" , in Asmodeus: Or, the Devil on Two Sticks by Alain René Le Sage (London: Joseph Thomas, 1841), p. xi. and Campbell (1849).Life and Letters of Thomas Campbell , ed. William Beattie (London: Edward Moxon, 1849), Vol. 2, p. 149.