We've been to St. Maarten quite a few times and never had any trouble finding someone to speak english. However, if you are really interested in learning the languages, why not. I speak a little French and can read it pretty well, what I found was that it is their own dialect of French and not what we are taught in school. Still, I could understand most of what was said. Since I have a slight southern accent, it's fun watching their faces when I reply to what was said in French. They think they're not being understood by a hick, it's fun to watch
Have a wonderful cruise!