De
The word de has many senses, like the word "of" in English. They are all related to the sense of "origin". "Of", "from", and "by" are the most common translations. Phrases like "man of honor", "house of congress", "field of battle", and "history of the world" all translate directly to Esperanto. It is used to form possessives: la oficejo de la muso is "the mouse's office". In the sense of "from", it is used to translate phrases like "from place to place" , "view from a distance", and "a gift from me". It also translates "since" in phrases like "since Monday" or "since the earthquake."
Finally, it translates "by" in phrases like "made by the elves"
(we'll learn about passive voice later) and "Hamlet, by Shakespeare." In this last sense, a new preposition, far, is becoming popular, but is not yet an official word in the language.
Information provided by the Esperanto HyperCourse Maintainer as part of the Esperanto HyperCourse.