This book provides a detailed description of Esperanto for linguists who are not familiar with the language. Its main aim is to demonstrate that Esperanto not only has complex system of etymology and word formation, but also of syntax and phraseology. Another aim is to determine to what extent the language has extended beyond its original conception in 1887. This work presents for the first time statistical and contextual analysis from a representative computer-based text archive using the latest techniques of corpus linguistics. Esperanto is an ideal object of study for linguists since it is the most widespread and best known example of an artificial language. In theory, Esperanto represents a regular, easily assimilated language designed for international use. Yet the language also came to be used socially among fellow enthusiasts, intellectually as a literary forum and politically for propaganda, especially in the communist era. Conservative estimates indicate 50,000 speakers, which is large by minority language standards. Yet Esperanto's status as a second language and ideological project has only recently attracted socio-linguistic fieldwork (Stocker 1995) and the language has undergone almost no critical linguistic analysis. Traditional descriptions point out that some syntactic elements of Esperanto are a priori rational systems which resemble few other languages, while most morpho-lexical elements are a posteriori and resemble donor languages such as Latin. Popular accounts of Esperanto rely on the '16 rules' which have led to the misconception that Esperanto has a minimal grammar. However, in the natural development of the language some original creole-like characteristics have emerged beyond Zamenhof's original design. For example, the uncertainty over aspect or tense in verbs, the increasing use of adverbs and prepositional-adverbs, or variable theme orientation in compound nouns. These processes are evidence of evolution in the language, although some have led to conflicts within the movement. There is particular debate about the degree to which it is possibile to control the language of what is essentially a discourse-community as well as a speech community (Swales 1990). All these factors make the language difficult to categorize according to traditional formulae. This volume outlines a linguistic description of the particularities of the language, from the morphosyntax to elements of phraseolgy. The description is based on a computational analysis of a written text archive (a corpus of 350 000 words). The corpus analysis reveals consistent patterns of phraseology which point to linguistic richness and dynamism. These patterns belie the receivced wisdom that artificial languages cannot really display natural complexity. [A version of this text in Esperanto can be seen on LINCOM'S web site]