De or het theatertraditie?

The correct Dutch article is:

de theatertraditie

Rule Words ending in -tie and -sie: almost always de. See the rule

How to use theatertraditie

the theatertraditiede theatertraditie
this theatertraditiedeze theatertraditie
that theatertraditiedie theatertraditie
our theatertraditieonze theatertraditie
your theatertraditiejouw theatertraditie
every theatertraditieelke theatertraditie
which theatertraditie?welke theatertraditie?
a big theatertraditie / the big theatertraditieeen grote theatertraditie, de grote theatertraditie