As in most European countries, in Holland it is expected to use the formal form “U” or “Uw”. You continue to use this formal address until the other person informs you that it’s okay to use the informal form “je/jij”. It is very common to address older people with the formal form and they might even continue to address you in this form because in the old days the formal address was much more commonly used.
Although the Netherlands is a relativelty small country, it has over thirty different regional dialects. The part of The Netherlands below the major rivers Rijn, Waal and Maas is historically Catholic and orientated more toward Belgium and France. Here dialects such as “Brabants”, “Limburg” and “Zeeuws” is spoken.
The part above the main rivers is more traditionally Protestant and orientated toward Scandinavia. Here dialects such as “Gronings”, “Drents” and “Achterhoeks” are spoken. “Fries” is actually an official language spoken in Friesland, a northern territory in Holland.
Online Dutch lessons for kids: dinolingo.com