This is an introductory course of Interlingua, the English version of the famous course by Ingvar Stenström, Sweden, which has been translated into 14 languages. "Interlingua - the language within languages". - Le diffusion global del vocabulario international - le parte del latino e del greco que supervive in le linguas moderne - es un facto historic. Interlingua es un registration de iste realitate linguistic, un denominator commun del idiomas de origine europee, e non un lingua artificial fabricate secundo arbitrari preferentias de un sol persona. - Interlingua can be learnt in a fraction of the time required to get just a superficial knowledge of a national tongue, and it gives you a means to communicate with those who speak Italian, Spanish, or Portuguese. In addition you tangibly increase your English vocabulary of cultural words and scientific and technological terminology.