Thank you SuStel for having the patience to explain all this. As a result of this thread, I'm actually for the first time optimistic that I'll succeed in reducing the frequency I misuse aspect.

But there's something which I still wonder.

jIH:
> 6. If I'm looking back from the present on quality verbs,
> but the quality described can't be described by the "used to", perfective is used:
> In the past the water has been hot
> In the past there was just one (or maybe two/three/more) occasion(s) when the water was hot
> (the second sentence describes the intended meaning)
> pa'logh tujpu' bIQ
> In the past the water often has been hot
> pa'logh pIj tujpu' bIQ
SuStel:
> This one I don't agree with. The words used to aren't necessary to avoid perfective;
> they're just a convenient, but incomplete, test to see if you're thinking in terms of perfective
> or not. Besides, I don't see why the water has often been hot couldn't be said as the water
> often used to be hot. So I don't think you're looking at used to in quite the right way.

Reading your reply, at first I couldn't understand the reason which made you disagree. But then I read your next comments:

SuStel:
> it means if you want to describe possessing a quality in the past,
> you're describing having that quality, not having completed having that quality
> Even if you're describing water that was only hot two or three times,
> you're still describing the being hot, not a completed action of being hot

(the former comment is from the < {je} "too" applying to the adverb > thread
http://lists.kli.org/pipermail/tlhingan-hol-kli.org/2022-March/019586.html))

And these two comments made me understand.

But there's still something I'm wondering. When would it be appropriate for us to put the {-pu'} on a quality verb? Because -if my understanding is correct- I can't think of an occasion when something like this would be needed. So could you write an example where the {-pu'} would be necessary on a quality verb?