one day; (on) a certain day
certain; some kind of; some sort of; of sorts
or; either ... or; maybe; perhaps; some ... and others ...; sometimes ... and at other times ...
on one occasion; once; at one point; at one time
to some extent; to a certain extent
someone (unspecified, but someone in particular); a certain person
some ... and others ...; sometimes ... and at other times ...; or; either ... or