What is "yeismo"

Yeísmo is a distinctive feature of many dialects of the Spanish language, which consists of the loss of the traditional palatal lateral approximant phoneme (written ) and its merger into the phoneme (written ), usually realized as a palatal approximant or affricate. It is an example of delateralization.

In other words, and represent the same sound . The term yeísmo comes from the Spanish name of the letter (ye). Now, over 90% of Spanish dialects exhibit this phonemic merger. Similar mergers exist in other languages, such as Italian, Hungarian, Catalan, Portuguese or Galician, with different social considerations.

Occasionally, the term lleísmo has been used to refer to the maintenance of the phonemic distinction between (spelled "y") and (spelled "ll").