De or het downstemming?

The correct Dutch article is:

de downstemming

Rule Words ending in -ing: almost always de. See the rule

How to use downstemming

the downstemmingde downstemming
this downstemmingdeze downstemming
that downstemmingdie downstemming
our downstemmingonze downstemming
your downstemmingjouw downstemming
every downstemmingelke downstemming
which downstemming?welke downstemming?
a big downstemming / the big downstemmingeen grote downstemming, de grote downstemming