Take the tour ×  My textbook contains the following sentence
(Regardless of whether you participate or not, kindly make sure
to RSVP by postcard.)  as an example of the expression
名詞＋にかかわらず. While I get the whole sentence and the にかかわらず, I'm
having trouble understanding this usage of しない. I know しない    •
as the ない形 of する   • as in 市内 (within the city)   • as in 竹刀
(bamboo sword)  but none of these three seem to make sense, and
the first one isn't even a 名詞.  Could someone please explain しない
in this context and the general pattern of how/when to use it?
share|improve this question add comment  2 Answers  This しない is
simply the negative of する; "don't do". The 参加するしない part of the
sentence means, regardless (～にかかわらず) of if you participate
(参加する) or if you don't participate (参加しない).  With this form for
"regardless of" (～にかかわらず; also could be ～を問わず), if often takes
contrasting or "opposite" ideas. So the 参加するしない is a compact way
to list the two choices of participating or not. I think it
would also be grammatica