EN
The aim of the article is to give an overview of a morphological structure of two planned languages, namely Esperanto and Interlingua with respect to their source languages. Among the large number of projects of international planned languages (also called (artificial) world languages, universal languages), in addition to the furthest developed and applied Esperanto (1887), Interlingua (1951) has played a certain role.The different target groups for whom the two languages were created are reflected by their vocabularies and morphological structures. Interlingua, virtually being an attempt to model Benjamin L. Whorf's 'Standard Average European', follows Romance model languages with regard to lexicon and word formation, it is historical-etymologically oriented, and is intended for an educated international elite that is familiar with European languages. Like its source languages, it possesses features of inflectional languages and knows analytic marking. Esperanto is communicative-functionally oriented, it has a very productive word formation system independent from model languages, and, therefore, is relatively easy to learn by people without a Euro-language background. It is characterized by a high degree of agglutination, but has properties of isolating languages as well as both synthetic and analytic features.Typical morphological properties of Esperanto and Interlingua will be compared: morphemes and their sources, morpheme compatibility, word categories and word formation processes, grammatical categories and paradigms (declination, conjugation). Examples and text samples including interlinear morphemic translation will provide insight into the two languages.