The Most Similar Languages to Czech

Czech is a Slavic language that is primarily spoken in the Czech Republic. Its linguistic traits, such as its complex grammar, extensive use of diacritics, and melodic sound, make it unique, yet closely related to several other languages. According to the eLinguistics.net analysis using specific software modules to assess linguistic relationships, the five languages most similar to Czech are Slovak, Polish, Slovene, Serbian, and Ukrainian.

1. Slovak (93.8)
   Czech and Slovak are often regarded as mutually intelligible languages. They were both once spoken in the former country of Czechoslovakia. As a result, their vocabulary overlap is extensive, with many words being either identical or differing only slightly in pronunciation or spelling.
2. Polish (91.5)
   Poland borders the Czech Republic and Slovakia, so it is no wonder the Polish language is extremely similar to Czech as well. Not only do they have Slavic roots, but they borrowed terms from Latin and German during historical periods of European influence. However, certain pronunciation and vocabulary can diverge.
3. Slovenian (88.0)
   Slovenian is a South Slavic language that shares a surprising number of features with Czech due to their common Slavic ancestry and shared linguistic traits. In fact, both Czech Republic and Slovenia were once part of the Austro-Hungarian Empire. Vocabulary overlaps in some basic and cultural terms, though less so than Slovak or Polish.
4. Serbian (84.3)
   Serbian, another South Slavic language, shares historical and cultural ties with Czech, stemming from interactions within the broader Slavic world. In fact, many cognates exist, though they may differ in pronunciation or form due to regional influences. However, Serbian’s sound system includes distinct features, such as pitch accent, absent in Czech.
5. Ukrainian (83.7)
   Ukraine is another country that borders Poland. However, as an East Slavic language, Ukrainian is slightly more distant from Czech compared to Slovak or Polish but still shares notable linguistic traits. One big difference is that Ukrainian uses the Cyrillic script, contrasting with Czech’s use of the Latin script.

(to be considered for the list, the language must be spoken by at least one million people)