Dutch language
Three Germanic dialects were originally spoken in the Low Countries: Frisian in the north and along the western coast; Saxon in the east (contiguous with the Low German area); and Franconian in the centre and south. It is the Franconian dialects that is designated as Old Dutch, and that would develop in Middle Dutch and later Modern Dutch. The division in these development phases is mostly conventional, since the transition between them was very gradual. One of the few moments linguists can detect somewhat of a revolution is when the Dutch standard language emerged and quickly established itself. The development of the Dutch language is illustrated by the following sentence in Old, Middle and Modern Dutch:

Q: Was the transition from Old Dutch to Modern Dutch gradual, or did it happen quickly?
gradual