My Zoëga dictionary doesn't seem to be consistent on verb morphology.
For the part participle, it will some time be in the masculine form or the neuter form...

for example: verit (neuter), hafðr (masculine)

Since the declension could be calculated from either form, why doesn't the dictionary show only the neuter form, or the masculine?
Is there anything to be taken from why it's in neuter here or masculine there?

And also, how do I know which form to use in a sentence? Where can the different forms be used?

I'm confused and in need of help. :P
Thanks.

-Sveinn