The proposed book by Boris Grigorievich Kolker is the most complete textbook of the Esperanto language in Russian. The author of the textbook is an Esperantologist, language teacher and translator. Member of the Esperanto Academy. Honorary member of the World Esperantist Association. For two decades he led mass Esperanto correspondence courses in the USSR. He taught Esperanto at the universities of San Francisco and Hartford. Currently teaching an advanced Esperanto course on the Internet. The textbook can be used for classes with a teacher in Esperanto language courses, as well as for correspondence and independent study of the language. For a wide range of readers.