There is absolutely no need to learn Dutch because everyone in the Netherlands speaks English, however learning some Dutch can be very interesting and it will really impress the locals. After a language course where you can learn the basics you could do a language exchange with a Dutch person. You teach someone your language and they will teach you some Dutch. Look for exchange ads on the third floor of the Central Library. Het Gilde has volunteers who want to teach the Dutch language in an informal way, a basic knowledge of the Dutch language is required (010) 4362844.