Old Czech

The Czech language developed at the close of the 1st millennium from common West Slavic. Until the early 20th century, it was known as Bohemian.

Among the innovations in common West Slavic is the palatalization of velar ch > š (vьšь, all), while s (vьsь) developed in the East and South-Slavic dialects.

Within West Slavic, Czech and Slovak separated from Polish around the 10th to 12th centuries. Some other changes took place during roughly the 10th century:

The disappearance of the odd yers strengthened the phonological contrast of palatalized (softened) and unpalatalized consonants, and resulted in alterations of epenthetic e and ∅ (null-phoneme). The contrast of the vowel quantity (length) was also strengthened. The depalatalization of consonants preceding e and ä took place later, thus the frequency of occurrence of palatalized consonants was lowered, but it strengthened the palatalization contrast at the same time. The change of ’ä > ě and ä > a took place at the end of the 12th century.

The vowels were front (ä, e, i, ě) and back (a, o, u), and the front ones had their back variants (allophones), and vice versa. The consonants were divided into hard (b, p, v, m, t, d, r, l, n, c, z, s, k, g, ch) and soft – palatal or palatalized (t’, d’, ř, l’, n’, c’, s’, z’, č, š, ž, j, ň). This division was cardinal for the later development.

The spirantisation of Slavic /g/ to /h/ is an areal feature shared by Ukrainian (and some southern Russian dialects), Slovak, Czech and Sorbian (but not Polish). This innovation appears to have travelled from east to west, and is sometimes attributed to contact with Scytho-Sarmatian. It is approximately dated to the 12th century in Slovak, the 12th to 13th century in Czech and the 14th century in Upper Sorbian.

In the nominal declension, the traditional division according to the word-stem ending was progressively replaced by the gender principle (masculine, feminine and neuter) There were also three grammatical numbers: singular, dual and plural.

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