I think I mis-stated my problems. Scan and endscan work fine and I think I understand their basic workings...it gets much more interesting when trying to do things like:

Scan while ssn='123-45-6789'
if there are equal birthdates in this scangroup;
check for equal firstnames;
delete one or more of them
endif
endscan
go on to the next ssn

The difficult piece is the creative code around and inside the scan loop that does these tests successfully!