De or het landencompetitie?

The correct Dutch article is:

de landencompetitie

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

How to use landencompetitie

the landencompetitiede landencompetitie
this landencompetitiedeze landencompetitie
that landencompetitiedie landencompetitie
our landencompetitieonze landencompetitie
your landencompetitiejouw landencompetitie
every landencompetitieelke landencompetitie
which landencompetitie?welke landencompetitie?
a big landencompetitie / the big landencompetitieeen grote landencompetitie, de grote landencompetitie