So you'd accept that the purpose clause in a noun phrase can have an object?
Sure. What else do you think is happening with qaSuchmeH 'eb? It's SoH qaSuchmeH jIH 'eb.
This makes it more like a relative clause.
All of the subordinate clauses can have subjects and objects. It's just the purpose clauses that are exceptional in that they can also NOT have subjects and objects. We simply don't know exactly when you can and can't drop the arguments. In general, purpose clauses attached to verbs have them and purpose clauses attached to nouns don't, but both sides of that are broken from time to time.
Unlike a relative clause, the head noun of a purpose clause is
NOT the subject or object of the clause.
It would be interesting to compare nouns with purpose clauses to relative clauses. There are enough similarities that one could stumble over the differences. One difference is that the purpose clause must still precede that which it modifies, correct?
Correct. A purpose clause precedes its head noun, while a
relative clause puts its head noun into a subject or object
position within the clause.
And the topic marker can make either subject or object be the head noun of a relative clause, but I don't get that this could happen with a purpose clause.
There would be no point. Since the head noun is not inside the
purpose clause, there is nothing to disambiguate.
Let's bring this back to Aurélie's original point: would ghItlhvam mughlaHghach chavlu'pu' be a better way to say "The ability to translate this manuscript has been achieved" (colloquially, "They've figured out how to translate this manuscript")?
Now you're trying to add an object to a verb before a -ghach is applied, and that's a whole other kettle of fish. I don't personally subscribe to the idea that -ghach'd verbs can be given arguments before the -ghach is applied; Okrand declined to comment on this possibility when given the chance. Start with a root verb, add one or more suffixes, then add -ghach. That's it. No prefixes, no objects, no subjects, no other syntactic nouns or clauses go inside the scope of the -ghach.
What you have above says This manuscript's ability to
translate has been achieved. That is, the manuscript has
been working to be able to translate something, and now it has the
ability to do so. What the manuscript is going to
translate, or how it's going to translate it, is not said.
It seems like a good choice to me, since -ghach nominalizes in such a way that mughlaHghach encompasses both "ability to translate" and "ability to be translated."
IT DOES NOT. mughlaHghach means only ability to translate. To mean ability to be translated, you'd need a verb X that means be translated, and then you could say XlaHghach. That verb is not mugh.
Are you getting mixed up by the word translate? In
English you can say things like "I can't say that; it doesn't
translate." That's not mugh. The message does not mugh;
it gets mugh'd. Klingon mugh is transitive.
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