jamaicans speak a local language called 'patois'. it is a mixture of african dialects, with english, spanish and french influences. they also speak english. some jamaicans speak english with a strong accent, though. the first time you hear a jamaican speaking english, you may have difficulties understanding him. but once you get used to their accent, it is not a problem talking to jamaicans. in some cases you will have to ask them to repeat several times what they are saying, especially when you talk to a jamaican not used to deal with tourists
A lot of people ask about tipping in Jamaica. I have found in my travels that most of the working Jamaicans barely make a sustainable salary and rely heavily on tips.
Therefore I tip pretty heavy when I get good service and when service is not all that great I still give them at least 15%.
Another thing to remember is to agree on cab fare before getting in a cab. A lot of tourists get trapped by not asking "how much" and get suprised when the driver charges what he wants, leading to an altercation. No one wants a hassle like that on vacation, so to avoid it always ask first, then tip accordingly.
I also am not in the practice of "haggling" with vendors. If I like something at a craft stall, I usually pay what the asking price is if I really want it. I think it is kind of rude to beat them up on pricing. Think about it, how many wood carvings do they have to sell a day to feed their families??
Be courteous and respectful of the locals and you will get it back.
At first I found Jamaicans to be taciturn. Perhaps they are just shy, maybe a little wary of tourists. Anyway, I was just persistently kind and in the end most of the hotel staff seemed to thaw a bit. Just don't expect Jamaicans to behave and act like Americans -- they aren't Americans and they have a distinctly different outlook and world view. Be tolerant and and open minded and you should be just fine!
If you are not staying in an all-inclusive resort, I recommend finding a friendly taxi driver early on in your stay, and sticking with him as much as possible. They appreciate extra tips and will be glad to help you out later on if they know you prefer them as your driver. Not uncommon for them to drive you somewhere, and pick you up hours later at a specified time if you request it.