Constructed languages introduced in the 1930s

English-based controlled language

international auxiliary language created by Arturo Alfandari

Khuzdul () is a fictional language created by J. R. R. Tolkien, one of the languages of Middle-earth, specifically the secret and private language of the Dwarves. He based its structure and phonology on Semitic languages, primarily Hebrew, with triconsonantal roots of words. Very little of its grammar is defined.

constructed language

Syldavian is a fictional West Germanic language created by Hergé as the national language of Syldavia, a fictional Balkan kingdom that serves as a major setting in many of The Adventures of Tintin stories. Hergé modeled the language on Brusselian, a dialect of Dutch spoken in and around Brussels. The entire corpus of the language has been analyzed by Mark Rosenfelder.

Esperanto reform of 1937

Medefaidrin (Medefidrin), or '''', is a constructed language and script created as a Christian sacred language by an Ibibio congregation in 1930s Nigeria. It has its roots in glossolalia ('speaking in tongues').