De or het grendelsteen?

The correct Dutch article is:

de grendelsteen

How to use grendelsteen

the grendelsteende grendelsteen
this grendelsteendeze grendelsteen
that grendelsteendie grendelsteen
our grendelsteenonze grendelsteen
your grendelsteenjouw grendelsteen
every grendelsteenelke grendelsteen
which grendelsteen?welke grendelsteen?
a big grendelsteen / the big grendelsteeneen grote grendelsteen, de grote grendelsteen