Mexican Spanish tends to fully pronounce consonants, including those at the end of words. This contrasts with dialects like Puerto Rican Spanish that might soften or skip consonants in final positions or before certain sounds.

Puerto Rican Spanish, like the language of every other Spanish-speaking area, has its distinctive phonological features ("accent"), which derive from the indigenous, African, and European languages that came into contact during the history of the region.

Apparently, one of Spain's medieval kings, usually identified as King Ferdinand, had a lisp. As a form of respect, and to please their king, Spanish people started speaking with this now characteristic sound called by some as the Spanish lisp.

Dropping the s Spanish in the Caribbean is faster and more relaxed than general Latin American Spanish. As with many Caribbean regions, Dominicans play it fast and loose with their s sound, omitting it nearly all of the time; I'd say they use this sound less than any other Spanish dialect.