|Native to||Crown of Castile|
|Ethnicity||Castillians, later Spaniards|
Old Spanish, also known as Old Castilian (Spanish: castellano antiguo; Old Spanish: romance castellano [roˈmantse kasteˈʎano]) or Medieval Spanish (Spanish: español medieval), was originally a colloquial Latin spoken in the provinces of the Roman Empire that provided the root for the early form of the Spanish language that was spoken on the Iberian Peninsula from the 10th century until roughly the beginning of the 15th century, before a consonantal readjustment gave rise to the evolution of modern Spanish. The poem Cantar de Mio Cid (The Poem of the Cid), published around 1200, remains the best known and most extensive work of literature in Old Spanish.
Spanish around the 13th century
The phonological system of Old Spanish was quite similar to that of other medieval Romance languages.
|voiced||d͡z||d͡ʒ ~ ʒ|
|voiced||v||z||ʒ ~ d͡ʒ|
The Modern Spanish system evolved from the Old Spanish one with the following changes:
The Old Spanish spelling of the sibilants was identical to modern Portuguese spelling, which, unlike Spanish, still preserves most of the sounds of the medieval language, and so is still a mostly faithful representation of the spoken language. Spanish spelling was altered in 1815 to reflect the changed pronunciation:
The letters ⟨b⟩ and ⟨v⟩ still had distinct pronunciations; ⟨b⟩ still represented a stop consonant [b] in all positions, and ⟨v⟩ was likely pronounced as a voiced bilabial fricative or approximant [β] or [β̞] (although word-initially, it may have been pronounced [b]). The use of ⟨b⟩ and ⟨v⟩ in Old Spanish largely corresponded to their use in Modern Portuguese, which distinguishes the two sounds except in northern European dialects. The phonological distinction of the two sounds also occurs in several dialects of Catalan (central and southern Valencian, an area in southern Catalonia, the Balearic dialect and Alguerese), though not in Standard Catalan from eastern Catalonia. When Spanish spelling was reformed in 1815, words with ⟨b⟩ and ⟨v⟩ were respelled etymologically to match the Latin spelling whenever possible:
Many words now written with an ⟨h⟩ were written with ⟨f⟩ in Old Spanish, but it was likely pronounced [h] in most positions (but [ɸ] or [f] before /r/, /l/, [w] and possibly [j]). The cognates of the words in Portuguese and most other Romance languages have [f]. Other words now spelled with an etymological ⟨h⟩ were spelled without any such consonant in Old Spanish: haber, written aver in Old Spanish). Such words have cognates in other Romance languages without [f] (e.g. French avoir, Italian avere, Portuguese haver with silent etymological ⟨h⟩):
Modern words with ⟨f⟩ before a vowel mostly represent learned or semi-learned borrowings from Latin: fumar "to smoke" (compare inherited humo "smoke"), satisfacer "to satisfy" (compare hacer "to make"), fábula "fable, rumor" (compare hablar "to speak"). Certain modern words with ⟨f⟩ that have doublets in ⟨h⟩ may represent dialectal developments or early borrowings from nearby languages: fierro "branding iron" (compare hierro "iron"), fondo "bottom" (compare hondo "deep"), Fernando "Ferdinand" (compare Hernando).
Old Spanish had ⟨ch⟩, just as Modern Spanish does, which mostly represents a development of earlier */jt/ (still preserved in Portuguese and French), from the Latin ct. The use of ⟨ch⟩ for /t͡ʃ/ originated in Old French and spread to Spanish, Portuguese, and English despite the different origins of the sound in each language:
The palatal nasal /ɲ/ was written ⟨nn⟩ (the geminate nn being one of the sound's Latin origins), but it was often abbreviated to ⟨ñ⟩ following the common scribal shorthand of replacing an ⟨m⟩ or ⟨n⟩ with a tilde above the previous letter. Later, ⟨ñ⟩ was used exclusively, and it came to be considered a letter in its own right by Modern Spanish. Also, as in modern times, the palatal lateral /ʎ/ was indicated with ⟨ll⟩, again reflecting its origin from a Latin geminate.
The Graeco-Latin digraphs (digraphs in words of Greek-Latin origin) ⟨ch⟩, ⟨ph⟩, ⟨(r)rh⟩ and ⟨th⟩ were reduced to ⟨c⟩, ⟨f⟩, ⟨(r)r⟩ and ⟨t⟩, respectively:
In common with other European languages before the 17th century, the letter pairs ⟨i⟩ and ⟨j⟩ and ⟨u⟩ and ⟨v⟩ were not distinguished. Modern editions of Old Spanish texts usually normalise the spelling to distinguish the pairs, as Modern Spanish does.
In Old Spanish, perfect constructions of movement verbs, such as ir ('(to) go') and venir ('(to) come'), were formed using the auxiliary verb ser ('(to) be'), as in Italian and French: Las mugieres son llegadas a Castiella was used instead of Las mujeres han llegado a Castilla ('The women have arrived in Castilla').
Possession was expressed with the verb aver (Modern Spanish haber, '(to) have'), rather than tener: Pedro ha dos fijas was used instead of Pedro tiene dos hijas ('Pedro has two daughters').
In the perfect tenses, the past participle often agreed with the gender and number of the direct object: María ha cantadas dos canciones was used instead of Modern Spanish María ha cantado dos canciones ('María has sung two songs'). However, that was inconsistent even in the earliest texts.
The future and the conditional tenses were not yet fully grammaticalised as inflexions; rather, they were still periphrastic formations of the verb aver in the present or imperfect indicative followed by the infinitive of a main verb.  Pronouns, therefore, by the general placement rules, could be inserted between the main verb and the auxiliary in these periphrastic tenses, as still occurs with Portuguese (mesoclisis):
When there was a stressed word before the verb, the pronouns would go before the verb: non gelo empeñar he por lo que fuere guisado.
Generally, an unstressed pronoun and a verb in simple sentences combined into one word.[clarification needed] In a compound sentence, the pronoun was found in the beginning of the clause: la manol va besar = la mano le va a besar.
The future subjunctive was in common use (fuere in the second example above) but it is generally now found only in legal or solemn discourse and in the spoken language in some dialects, particularly in areas of Venezuela, to replace the imperfect subjunctive. It was used similarly to its Modern Portuguese counterpart, in place of the modern present subjunctive in a subordinate clause after si, cuando etc., when an event in the future is referenced:
|Latin||Old Spanish||Modern Spanish||Modern Portuguese|
|acceptare, captare, effectum, respectum||acetar, catar, efeto, respeto||aceptar, captar, efecto, respecto and respeto||aceitar, captar, efeito, respeito|
|et, non, nos, hic||e, et; non, no; nós; í||y, e; no; nosotros; ahí||e; não; nós; aí|
|stabat; habui, habebat; facere, fecisti||estava; ove, avié; far/fer/fazer, fezist(e)/fizist(e)||estaba; hube, había; hacer, hiciste||estava; houve, havia; fazer, fizeste/fizestes|
|hominem, mulier, infantem||omne/omre/ombre, mugier/muger, ifante||hombre, mujer, infante||homem, mulher, infante|
|cras, mane (maneana); numquam||cras, man, mañana; nunqua/nunquas||mañana, nunca||manhã, nunca|
|quando, quid, qui (quem), quo modo||quando, que, qui, commo/cuemo||cuando, que, quien, como||quando, que, quem, como|
The following is a sample from Cantar de Mio Cid (lines 330–365), with abbreviations resolved, punctuation (the original has none), and some modernized letters. Below is the original Old Spanish text in the first column, along with the same text in Modern Spanish in the second column and an English translation in the third column.