antequam as in "mielőtt" in Hungarian? I think as we have

epeta adv. “following that, thereupon, thence, whereupon”, we could surmise that *apata, *apta could be an option?

If Tolkien just hadn't gone switching the meanings of APA, EPE, nóvo/nó- constantly... Well, there's at least always the root NIB ('face, front') which may also be of help.

Any mind-eroding conditions are certainly countered when one attempts to come up with ways to say the same thing — e.g. *lartie-nca i "without awaiting that" (with a "neo-abessive" on infinitive II!).

It feels rewarding to also arrive at some mercifully short items like quië that can "step in" for It. che, Icel. en & F kuin in a paraphrase (paired with an infinitive [< PHER, RAT..] or a comparative adverb).

Well if you could just elaborate on your last two paragraphs, Sami, I fear I don't entirely get your meaning...

Hm? I certainly translated my neologism in the second.. as I said, it is a paraphrase for "before" (in a situation where some action needs to be taken), using *larta- < DAR (ex libris PPQ), -enca (PE17:167), and i "daß".

In the third paragraph I was alluding to a somewhat common phenomenon in conjunction phrases IRL which to my mind the examples ought to illustrate; the small semantic connecting word — often the same as the word for "than" [Q lá; compare #-la] — and ways to deal with it in paraphrases (while also trying to keep the syllable count down to a sensible maximum). Then, if you write for instance (a)manwa quië "to prepare oneself, whenever...", the whole makes sense also once you add any expected continuation (i.e., continue the sentence). Perhaps self-obvious — but it's important to perceive how it's not just about tossing an adverb or whatnot there in between.

+ܤܡܝ ܦܠܕܢܝܘܤ
oh there's nothing wrong with your comment there, it's my brain that's functioning too slow on a Monday like this.

I can't say in all honesty I would recognize *lartienca for what it's intended to be if I saw it in a text, not at first glance.

Do you think the infinitive in -ie can definitely stand in for Spanish gerundio, or Polish transgressive, Magyar adverbial participle? a rike anrikie points to that I think.

It is somewhat tempting to always proceed from, say, Finnish when looking at Q forms (especially verbal nominatives like enyalië that can even take case endings), but sb more versed in the subject of course has common sense to keep his eyes more open and remember to compare everything to Indo-European etc. as well, also because Quenya has fewer cases and more prepositions than Finnish. In that sense it is more like Baltic or even Russian. Even so, in the Markirya poem we have instead the ACTIVE PARTICIPLE (Proper) utilized in a way reminiscent of adverbial participles (a.k.a. gerunds), with man tiruva cirya cálë fifírula? instead of -ië in ø-essive (or locative).

However, given the "rare" form cárienwa in PE17 I can't absolutely claim there wouldn't be some way to utilize a verb to connote "AFTER doing st" (the Finnish equivalent [V-t]tua, [V-t]tyä +pn suff looks like sth. derived from the ultimate passive participle, too).