"The discussion ends."
Translation:De discussie eindigt.
'Beëindigd' (NOT beëindigt, which you proposed. The -t ending doesn't exist for this verb in this form. These are hard, I know!) means 'ended'. E.g.: De discussie is beëindigd = The discussion has ended.
Beëindigen certainly can be conjugated like any other verb.
The difference is:
- Eindigen = intransitive
- Beëindigen = transitive
So by using beëindigen you would need an object that the subject ends/finishes, e.g. Hij beëindigt zijn carrière (He ends his carreer).