sheísmo

Sheísmo is a phonetic variation found in some Spanish dialects in which the sounds written by the letters “ll” and “y” are pronounced as the voiceless postalveolar fricative [ʃ], the “sh” sound. It is a regional development within the broader phenomenon of yeísmo, where both letters are merged with a single phoneme; in sheísmo, that merged phoneme is realized as [ʃ] rather than as [ʝ] (or, in other varieties, [ʒ]). The related variant using [ʒ] is called zheísmo.

Geographically, sheísmo has been documented most prominently in urban varieties of the Río de la Plata region, particularly in Buenos Aires and Montevideo, where younger speakers and certain social groups have shown the influence. It has also appeared in some other Argentinian and Uruguayan communities and, more sporadically, in parts of Chile and adjacent areas. The feature often coexists with other regional sound patterns, and its presence can vary within a city or even within neighborhoods.

Phonologically, sheísmo affects the orthographic pair ll and y in position where they would otherwise be pronounced as a palatal sound or as part of a yeísmo merger. In practice, words such as “llama” or “hoy” may be realized with a [ʃ] articulation for these sounds in the affected speech communities. Because pronunciations can differ by speaker and context, sheísmo is typically described as a regional and social variation rather than a universal feature of any single Spanish dialect.

See also: yeísmo, zheísmo.