De or het assembleevergadering?

The correct Dutch article is:

de assembleevergadering

Rule Words ending in -ing: almost always de. See the rule
Meaning (Dutch) (politiek) bijeenkomst van een parlement of algemene vergadering

How to use assembleevergadering

the assembleevergaderingde assembleevergadering
this assembleevergaderingdeze assembleevergadering
that assembleevergaderingdie assembleevergadering
our assembleevergaderingonze assembleevergadering
your assembleevergaderingjouw assembleevergadering
every assembleevergaderingelke assembleevergadering
which assembleevergadering?welke assembleevergadering?
a big assembleevergadering / the big assembleevergaderingeen grote assembleevergadering, de grote assembleevergadering

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).