Czech differs from some other Slavic languages in the characteristic sentence intonation, the first-syllable word accent, the absence of elision, the use of the Latin alphabet instead of the Cyrillic, the exceptionally free word order, and the prominence given to vocalic r and l. The quality of a ringing, staccato speech distinguishes it from other Western Slavic languages.

Before the 11th century Czechs wrote in Old Church Slavonic, the first Slavic literary language, which had been developed by Saints Cyril and Methodius for missionary work in Greater Moravia (now Slovakia and the eastern region of the Czech Republic). In the 11th century two important linguistic events took place: In the West, including Bohemia, Moravia, and Slovakia, Latin replaced Old Church Slavonic for church and literary use, and the regional Slavic dialects began to develop into separate languages. After centuries in which Czech was a despised and suppressed peasant tongue, the 14th-century Bohemian religious reformer John Huss (Jan Hus) standardized Czech spelling. His stature as a national hero endowed the peasant vernacular he used with a new dignity. The work of Huss was consolidated and advanced during the 15th and 16th centuries by the Unity of Brethren, a Protestant sect later known as the Moravian Brethren. The writings of this sect stabilized the Czech language and determined its future as a literary language. Except for the growth of vocabulary, the Czech and Slovak languages have not changed significantly since the 16th century.