"Torg and Mara ate some delicious gagh in your mother's house."
Translation:SoSra' juH qachDaq qagh 'ey luSop torgh mara je.
In English there is some meaning an unspecified number and there is a different use of some that serves the same purpose as a or an for uncountable or plural things. The word 'op translates only the former. For the latter, it is not translated, the way a, an and the are not. As a rule of thumb if you could leave some out of the English and have the same meaning, just perhaps sounding less smooth, then don't use 'op in Klingon.
qach bIngDaq QongtaH targhmey. [Some] targs are sleeping under the building.
qach bIngDaq QongtaH 'op targhmey 'ach narghpu' latlhmey. Some targs are sleeping under the building, but the others have escaped.
Apologies if I just used vocabulary you haven't hit yet on the course. I know pretty much what vocabulary is used, but as I wasn't there for the painful process of sorting it, I don't have it ingrained what comes where.
In English, using some in this way indicates an unspecified amount, but implies there is an expected normal range implied.
A simplified example:
Torg ate some food.
You don't know exactly how much food Torg ate, but you expect that he didn't completely stuff himself.
Torg ate food.
There is no indication of how much food Torg ate, but also no associated sense of whether he ate a reasonable amount.
Klingon doesn't have a way to make this distinction. The best you can do in Klingon is to say Soj Soppu' torgh Torg ate food.
It is perhaps a bit unfair to ask a student to drop this kind of some without explaining why they're doing it.