This book will be a descriptive grammar of the Esperanto language invented by L. L. Zamenhof, which will be complete and comprehensive in regards to a) the grammar of Esperanto as first outlined by Zamenhof in Fundamento de Esperanto and other foundational documents, and b) Esperanto as it is spoken today by the most committed Esperantists. (Proposed reforms to the Esperanto language will be discussed if they have serious support from a significant fraction of Esperanto enthusiasts). This book was started practically on a dare from the August 2006 issue of Bob's Poetry Magazine, in which Robert Happelberg boasted that he could print a complete and comprehensive grammar of Esperanto in just one 6 by 7 inch page. While this is obviously wrong, it's not too far off the mark. When completed, this book will require several standard size (8.5 by 11 in the USA) pages, but will still be much shorter than a complete grammar of a natural language like English or Slovene. In view of this goal, the number of examples provided for each concept will be kept to a bare minimum. Those wishing to build their Esperanto vocabularies are also referred to the Esperanto textbooks. It is acceptable in the beginning to word the text in an accessible manner like in a textbook, but the goal should be for all the text to be technical with a full command of linguistic jargon. Illustrated with 10 images.