Belgium has three official languages: French, Dutch and German. German is only spoken by a small minority of the population, who live along the German border. The form of Dutch spoken in Belgium is known as Flemish, and is the official language in Flanders, to the north of the country.
French is the official language in Wallonia in the south. Brussels has both Dutch and French as its official languages, but in practice more than three quarters of its inhabitants speak French as their main or only language. It is sometimes said that English is the 4th unofficial language, as it is widely spoken in Belgium, and many Belgians learn English from an early age. If living in Belgium, however, it will be helpful to be able to understand and speak at least one of the official languages.
The Euro is now the official currency of 12 EU member states including Belgium. The first Euro coins and notes were introduced in January 2002.
Until 2002 the Belgian Franc was still in circulation; but, not any more. Make sure you don't have Belgian Franc's given to you for change. They are now worthless..