Linguistically, the Czech

Czech language

Czech is a West Slavic language with about 12 million native speakers; it is the majority language in the Czech Republic and spoken by Czechs worldwide. The language was known as Bohemian in English until the late 19th century...

 and Slovak

Slovak language

Slovak , is an Indo-European language that belongs to the West Slavic languages .Slovak is the official language of Slovakia, where it is spoken by 5 million people...

 languages form a language continuum, eastern Slovak dialects then blend into the Rusyn language

Rusyn language

Rusyn , also known in English as Ruthenian, is an East Slavic language variety spoken by the Rusyns of Central Europe. Some linguists treat it as a distinct language and it has its own ISO 639-3 code; others treat it as a dialect of Ukrainian...

. Czech exists in two forms (excluding the four Moravia

Moravia

Moravia is a historical region in Central Europe in the east of the Czech Republic, and one of the former Czech lands, together with Bohemia and Silesia. It takes its name from the Morava River which rises in the northwest of the region...

n and two Silesian

Czech Silesia

Czech Silesia is an unofficial name of one of the three Czech lands and a section of the Silesian historical region. It is located in the north-east of the Czech Republic, predominantly in the Moravian-Silesian Region, with a section in the northern Olomouc Region...

 dialects): literary Czech and colloquial Czech. The standard Slovak language is closer to literary Czech, especially in phonology and morphology. The differences between parts of the vocabulary of some Slovak dialects are rather big, comparable to the differences between standard Slovak and Czech. The description below sums the main differences between standard Slovak and Czech.

• Slovak graphemes that do not exist in the Czech language are ä, ľ, ĺ, ŕ, ô, ia, ie, iu, dz, dž (see Pronunciation for Czech and Slovak language). Czech graphemes that do not exist in the Slovak language are: ě, ř and ů.
• Slovak has the following phonemes which Czech does not have: /ʎ/, /rː/, /lː/, /æ/ (this one only in higher-style standard Slovak, or some dialects), and the diphthongs /i̯a/, /i̯e/, /i̯u/, /u̯ɔ/; and on the contrary, Czech has /r̝/.
• Czech uses peculiar pitch contour
  Pitch contour
  In linguistics, speech synthesis, and music, the pitch contour of a sound is a function or curve that tracks the perceived pitch of the sound over time....
  
  , not present in Slovak (or Moravian dialects).
• Slovak, unlike Czech, uses palatal consonant
  Palatal consonant
  Palatal consonants are consonants articulated with the body of the tongue raised against the hard palate...
  
  s more frequently (that is, is phonetically "softer"), but there are some exceptions (SK batoh, dekan; CZ baťoh, děkan [ďekan]).
• The phonetic assimilation and a kind of "liaison" are much stronger in the Slovak language
• The Slovak grammar:
  • is somewhat simpler (i.e., more regular) than Czech literary language grammar, since the present-day Slovak language standard was codified only in the 19th century.
  • has different declension and conjugation endings and paradigms
  • has 6 morphological cases (see Slovak declension
    Slovak declension
    The Slovak language, like most Slavic and Latin languages, is an inflected language, meaning that the endings of most words change depending on the given combination of the grammatical gender, the grammatical number and the grammatical case of the particular word in the particular sentence:a)...
    
    ) - the vocative (officially not considered a separate grammatical case anymore) is almost lost, while the Czech vocative is well alive
• Some basic Slovak is similar to the Czech language, and a few (almost) identical words have different meanings. The differences are mostly of simple historical origin (for example the word hej mentioned below was used in Great Moravia
  Great Moravia
  Great Moravia was a Slavic state that existed in Central Europe and lasted for nearly seventy years in the 9th century whose creators were the ancestors of the Czechs and Slovaks. It was a vassal state of the Germanic Frankish kingdom and paid an annual tribute to it. There is some controversy as...
  
  ). As for professional terminology, except for biology (esp. all names of animals and plants), the Czech terminology was mostly taken over (in Slovakized form) for practical reasons. The Czech-Slovak Dictionary of Different Terms (1989, Prague) contains some 11,000 entries (without professional terminology):
  • Examples of basic different words are: yeah (SK hej – CZ jo), if (SK ak – CZ jestli, jestliže, -li), Good bye (SK dovidenia – CZ nashledanou), January (SK január – CZ leden), cat (SK mačka – CZ kočka), to kiss (SK bozkať – CZ líbat), now (SK teraz – CZ teď, nyní), goods (SK tovar – CZ zboží), he/she/it is not (SK nie je - CZ není)
  • Examples of typical small differences: endings (SK -cia, -dlo, -ť, -om – CZ -c(i)e, -tko, -t, -em), expressions (SK treba, možno – CZ je třeba, je možné / je možno)
  • Examples of words with different meanings : SK topiť (to melt) – CZ topit (to heat), SK horký (bitter) – CZ horký (hot) but hořký (bitter)
• The Czech language has no equivalents for many Slovak words and vice versa. Examples of no Czech equivalents: prepositions (popod, ponad, sponad), verbs (ľúbiť, povynechávať, skackať, siakať), nouns (kúrňava, kaštieľ, hoľa, grúň), pronouns (dakto, voľakto, henten)
• The Czech language does not have the Rhythmical Rule (see Slovak language)
• Slovak uses the passive voice
  Passive voice
  Passive voice is a grammatical voice common in many of the world's languages. Passive is used in a clause whose subject expresses the theme or patient of the main verb. That is, the subject undergoes an action or has its state changed. A sentence whose theme is marked as grammatical subject is...
  
  formed like in English less than Czech, and prefers the passive voice formed using the reflexive pronoun s/so (like in Spanish language) instead.