Abstract After a brief outline of the principal episodes in the external history, the chapter surveys the principal aspects of phonology, orthography, morphology and syntax of Catalan and its principal dialects (spoken in Catalonia, France, Andorra, and Sardinia). Topics dealt with include: territory, geographical dialects, and demography; salient diachronic features; stressed and unstressed vowels; consonants (dialectal and allohponic variation, deletion, assimilation, voicing and devoicing), syllable structure and stress; writing systems and orthography; nominal morphology; verb inflection; articles; word formation; syntax of verbal clitics; subjects; objects.