Phonological history of Spanish coronal fricatives

In Spanish dialectology, the terms distinción, seseo and ceceo are used to describe the opposition between dialects that distinguish the phonemes /θ/ and /s/ (distinción), and those that exhibit merger of the two sounds (neutralización) into either /s/ (seseo) or [s̄], a sibilant fricative similar to /θ/ (ceceo).

Dialects that distinguish the two sounds, and thus pronounce the words casa "house" and caza "hunt" differently, are described as having distinción, whereas the dialects that lack this distinction and pronounce the two words as homophones are described as having seseo if both words are pronounced with [s] or ceceo if both words are pronounced with [s̄].

Seseo is typical of the Latin American and Canarian dialects and some dialects of central Andalusia, whereas distinción is typical of most dialects in Spain, except in much of Andalusia and the Canary Islands. Ceceo is found in some dialects of Spain, in the southernmost part of Andalusia.