Alternatively, it could be pantha- but I wasn't sure.

The ie suffix is an abstract noun/gerund suffix in Quenya and would not be used in verbal formations. It would need to be S pantha- if it developed from primitive *panta-, or abantha- if it were a more direct cognate of EQ. apanta- "reveal". Maybe the a- prefix is some kind of intensifier.

Since the root PAT = "open" also appeared in the Etymologies, moving forward the EQ and G derivatives of this root seems reasonable to me.

Actually, looking at this a second time, in the Etymologies Q. panta- "open" has a Noldorin cognate panna-, pointing to a primitive form of *patna-, not *panta-. This makes more sense, since nasal-infixion was often use for primitive past tenses and therefore is unlikely for primitive verb formation.

Unfortunately, you can't use panna- for "reveal" since it already means "open", but maybe abanna- would work as the cognate of EQ apanta-. Alternately, maybe you can use et + panna- "out open" > ephanna-.

+Paul Strack I was aware of N panna-. But I though with tha, I could make it mean "to make clear/open". I have a bad habbit of taking examples from my mother language (Turkish) and it has "açık" for "(something) open" and "açıkla-" for "reveal, explain, make clear". Turkish "-la" suffix and Sindarin's "-tha" are the same, from what I have gathered.

Actually, "make open" would be a pretty good construction for "reveal". Since the root is PAT, I think the primitive form would be *patta- > S patha-.

Of course it's a good thing to compare with other languages one know. I've now read about the ta -> tha ending in the Gateway, and yes, it seems like it would work with patha-.

Edit: patha- it is then! :)

+Ekin Gören if you look, the form that was suggested was *patha-

+Tamas Ferencz Oh I see now. Thank you for notifying me. :)