The Spanish of the Greater Antilles
My advice to learners of Spanish often begins with the observation that not all native speakers are created equal when it comes to their being appropriate models to imitate. Native speakers of any language often commit what are known as native errors. Think of how many Americans you have heard say "Have you ever went ...?"
The next piece of advice I give to beginners follows from the previous observation. I tell them to learn "textbook" Spanish -- that is, learn it the way it is taught and presented in textbooks before attempting to speak any particular dialect of the language. Learn to do it right before you permit yourself the luxury of being tempted to imitate native speakers, with all their dialectical oddities.
It is fun to learn to at least recognize dialects -- and it can be intellectually gratifying to correctly guess where a person is from by their accent. I have never found a Spanish speaker who is sensitive about their regional accent -- there is a lot of local pride. Maybe it goes with their local fútbol club...
In terms of grammar, Spanish is quite uniform around the world. In terms of lexicon; local preferences are usually found in common items, household vocabulary, foods, clothing and so forth.
The major dialects of Spanish in the Americas lend themselves to geographical labels. The dialect of the Caribbean area is often described as antillano -- for the Spanish as spoken in the Greater Antilles (Puerto Rico, Hispaniola and Cuba -- Jamaicans speak a dialect of English). Although there are distinguishing features within this category, one curious feature about this dialect, in the broadest terms, is that many, if not most speakers drop S if it falls at the end of a syllable. There are two reasons for this. First, Spanish speakers in Seville and other southern and western regions of Spain, including the Canary Islands, were the principal settlers of this region and they tend to drop S at the end of syllables. Coincidentally, the majority of the Africans who were brought there as slaves come from the Ivory and Gold Coast area of Africa where, according to one of my colleagues who is from that region and speaks several of the languages, the majority of their languages do not have S at the end of syllables. So, as this large population of Africans learned Spanish, they never heard any S at the of syllables anyway! Antillanos also tend to palatalize and nasalize final -n -- making it sound like -ng.
For readers familiar with the grammar of Spanish, another feature of antillano is the archaic use of the imperfect subjunctive as an equivalent of the pluperfect indicative. It is a reminder of the Golden Age of Spain -- the swashbuckling era of pirates, privateers and corsairs, yes: Pirates in the Caribbean!