Thread:User talk:Mormegil/"Česky" or "Čeština"?/reply (3)

Well, as Michawiki said, „česky“ is an adverb, while „čeština“ is the name of the language. As there is no simple definition of the contents of the $coreLanguageNames list, we have to decide what should be used in the only use case, i.e. the interlanguage list.

I would say both of the variants could be used there, and looking to the other Slavic languages, I see e.g. “Slovenčina”, which is an equivalent of “Čeština”, but e.g. “Polski” is (IIANM) equivalent of “Česky”.