What language is spoken in St Martin generally depends on where on the island you are located. For instance, if you choose any of the St. Martin vacation rentals on the island's northern side, you'll find that most businesses, staff, and restaurants are mainly French, English, or Creole-speaking.
Likewise, if you are staying somewhere in beautiful Sint Maarten, the official language is Dutch, but you'll find that most people also speak English. As one of the most popular Caribbean Islands vacation destinations, you'll find that most restaurants, taxi drivers, and staff can find a common language to facilitate your needs.