In all languages we have - following the leading linguist Karl Bühler with his “Sprachtheorie” (1934) – to distinguish three fundamental functions of language, namely presentation, expressivity and appeal. One has to look for special possibilities of realization of the appeal function in single languages. One possibility of appeal function is sentence intonation, also word order or the use of special lexemes. A very important fact in Bulgarian is the use of the vocative in direct speech, used for persons, but only in the singular. The vocative is to be used in some other European languages, but also in Balkan languages like Rumanien, Greek and Serbian.