The \quote and \quotation macros surround text with quotation marks. These are made language dependent.
In dutch the old way was an opening mark at the baseline and closing at the top of the letters; ConTeXt has been programmed this way.
However, the lower quotation mark is less and less used in Dutch (vide Jan Renkema, Schrijfwijzer, 2002, p.382) and the English variants are now commonly used.

This leads to two questions:
1. is there a setup-macro that can be used? (switching language around before quote and changing back inside is a bit awkward);
\setupdelimitedtext[..][..]  is not documented in the manual, is this the one to use, and how?
I tried this but could not effect a change and from the code I could not deduce what to change.
2. is this a case for changing ConTeXt's default for Dutch?

Hans van der Meer