The primary language is, unsurprisingly, Czech. As there is a large Slovak population, the Slovak language is often heard, and both languages are mutually intelligible up to a degree. Czechs are extremely proud of their language, therefore you won’t find many signs in English even in Prague (outside of the main tourist areas). Many elderly people, particularly outside of major cities, are also unable to communicate in English, so it’s a good idea to learn some Czech or Slovak before you arrive. However, since English has been taught in most schools since 1990, most young people speak at least some of it.
The majority of Czechs speak a second and, in certain cases, a third language. English is the most commonly spoken language, particularly among young people. German is most likely the most commonly spoken second language among the elderly. Under communist control, Russian was required in all schools, thus most individuals born before 1975 spoke at least some Russian (and often pretty well). However, the communist period and the Soviet-led invasion of 1968 (as well as today’s Russian-speaking criminal gangs) have given this phrase a bad connotation. It is particularly ineffective with younger people since, contrary to popular belief, it is not mutually intelligible with Czech (beyond few comparable terms and short phrases), and English has largely replaced it as the preferred foreign language. Other languages, such as French or Spanish, are taught at certain schools, but don’t rely on it. Some basic phrases or short sentences in other Slavic languages may also be understood (Polish, Bulgarian, Serbo-Croatian, etc.)
The Czech and Slovak languages are very difficult for English speakers to comprehend since, like their sisters, they may be tongue-twisting languages to learn (particularly Czech) and need time and effort to master, especially if you are unfamiliar with other Slavic languages, such as Russian. However, if you can master the alphabet (and the corresponding letters with accents), then pronunciation is simple since it is consistent – Czechs and Slovaks enunciate every letter of a word, with emphasis on the first syllable. The combination of consonants in certain words may seem to be mind-bogglingly difficult, yet it is well worth the effort!
The Czech language contains many regional dialects, particularly in Moravia. Some dialects are sufficiently dissimilar that they may be misinterpreted even by a native Czech speaker from another area. However, all Czechs understand and should be able to speak standard Czech (as spoken on TV, printed in newspapers, and taught in schools) (but some are too proud to stop using their local dialect). Some of them can’t even speak basic Czech yet can write it well.
Czech and Slovak vocabulary are close, with a few terms that are not understandable. The younger generation born after Czechoslovakia’s breakup is growing apart in the two different nations, and they have difficulty understanding one another.