De or het theeveiling?

The correct Dutch article is:

de theeveiling

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

How to use theeveiling

the theeveilingde theeveiling
this theeveilingdeze theeveiling
that theeveilingdie theeveiling
our theeveilingonze theeveiling
your theeveilingjouw theeveiling
every theeveilingelke theeveiling
which theeveiling?welke theeveiling?
a big theeveiling / the big theeveilingeen grote theeveiling, de grote theeveiling