Fundamento de Esperanto(**)
(= The Foundation of Esperanto), includes La
It is the first document, which described the language "Esperanto", written by Zamenhof.
That document was edited on July 26, 1887 in Russian, then later in French, English, German and Polish.
It was directed at educated people, which had a good knowledge of the grammar of their own language, and maybe, of one or more languages - as it should be your case.
Based on this document, the language spread out.
Even if Esperanto considerably evolved since then, this document is considered the only obligatory authority over Esperanto(**) and is thus unchangeable.
"La Fundamento" consists of four parts(**)
In this course, you will get acquainted with the Grammar. In the Exercises you will learn a few words, but If you want to speak fluently, you'll have to learn more vocabuary. Go on with the Vocabulary(**).
Don't attempt to understand
every detail of the grammar right away: it's the
purpose of the Exercises, to enable you to better
somewhat sketchy rules.
You should be capable of finding out the grammar rules by yourself, based on the Exercises. This is the most natural way to learn a language. If you cannot figure out a rule, just leave a note to yourself and come back to it a few days later. If you do not find a satisfactory explanation by yourself, send a message to the newsgroup soc.culture.esperanto. After some time, depending on your diligence, your brain will become accustomed to the subtleties of the language, and you will be able to turn to a more difficult task.
You might find it useful to dowload "The Esperanto Teacher"(**) (by Helen Fryerd) and print it.