Czechoslovak language

The Czechoslovak language (jazyk československý, Československý jazyk) was a political sociolinguistic concept used in Czechoslovakia in 1920–1938 for the definition of the state language of the country which proclaimed its independence as the republic of two nations, i.e. ethnic groups, Czechs and Slovaks.

The Czech and Slovak languages are two closely related and partially mutually intelligible West Slavic languages; they form their own sub-branch, called the Czech-Slovak languages. In practice, in the international discourse and documents, the role of "Czechoslovak" was played by Czech. However, in local speech in public discourse, and media, it was generally a form of Czech as spoken in the capital Prague (i.e. either Standard Czech formally or Common Czech informally) with limited introduction of some Slovak vocabulary. Meanwhile, the Constitution of 1920 and its derivative acts allowed the usage of minority languages provided that they were spoken by not less than 20% of the local population of certain areas.

Officially, the 1920 constitution was superseded on 9 May 1948 by the Ninth-of-May Constitution where the concept of the official language was omitted. The Czech and Slovak languages became de facto official in the parts of the country where they were spoken by the respective ethnic majority, while Czech also preserved the role Czechoslovak had in international affairs.

History
The Czech-Slav Society (also called the Society for the Czechoslovak Language and Literature) was created in 1829 by students of the Evangelical Lyceum in Bratislava (German: Preßburg or Pressburg), and became an important entity in the Slovak national movement.

In 1836, Ľudovít Štúr, the leader of the Slovak national revival in the 19th century, wrote a letter to the important Czech historian František Palacký. Stating that the Czech language used by the Protestants in Upper Hungary had become incomprehensible for the ordinary Slovaks, Štúr proposed to create a unified 'Czechoslovak language', provided that the Czechs would be willing to use some Slovak words – just like Slovaks would officially accept some Czech words.

However, in the first half of the 20th century, the radical concept of 'Czechoslovakism' set forward the Czech language as the literary norm, while the Slovak language was considered to be a local dialect, as was the Moravian language. The concept of 'Czechoslovakism' was used to justify the establishment of Czechoslovakia to the world, because otherwise the statistical majority of the Czechs as compared to Germans would be rather weak.

Language legislation
On 29 February 1920, the National Assembly of the First Czechoslovak Republic adopted the Czechoslovak Constitution and, on the same day, a set of constitutional laws. The Language Act (Jazykový zákon) 122/1920 Sb. z. a n., on the grounds of § 129 of the Constitutional Charter (Czech Ústavní listina Československé republiky) has set the principles of the language regulations, where § 1 ruled that the Czechoslovak language "jazyk československý jest státním, oficielním jazykem republiky" ('is the state, or official language of the republic').