So "farmor" = father's mother and "mormor" = mother's mother (and same with grandfather)?
Yes. English doesn't distinguish between paternal and maternal grandparents but Swedish does.
Mat. Grandparents = Mormor, Morfar / Morföräldrar
Pat. Grandparents = Farmor, Farfar / Farföräldrar
Great grandparents go like Farfars far and farmors far, farfars farfar and farmors farmor etc.
Children go the same way: Barnbarn, dotterdotter, sonson etc.
Shouldn't "our house" also be accepted since it's idiomatic? You can say "come to my house" and mean an appartment for example.
Our place = our house = ours
So what does "hos" actually mean? Like is it a verb, or is it an adjective? Does it, on its own, mean "at home/at x's place" or is it a case of excluding a preposition for no real reason? Also, why does "oss" come after it here? Why don't we use a possessive pronoun to say whose house in this scenario?
hos is a preposition. There's no real counterpart in English in this case. A grammatically similar construction is with us, but then that would be med oss in Swedish. Rather it's that in English, you have the set expression 'at our place' that you use instead of preposition + pronoun. In French for instance, they have the same construction as we do, they'd say chez nous to express this.
There's no word for 'granny' that is generally used. Children sometimes use versions like fammo and mommo but those are far from being as normal as 'granny' is in English.
It would probably be paternal grandmother, not paternal mother. If it's not accepted, report it.
Sounds a lot like the TTS is saying "Farmor är pos oss" in the "slow speech" version (sounds fine in the fast speech, though).
'stays with us' implies that grandmother resides with us. But the Duolingo sentence doesn't imply that. All it says is that grandmother is (currently) inside our house.
You can't really say "the grandmother" in Swedish, not in a way that sounds right at least. Either undetermined "en mormor" (a grandmother) or a possessive "min/din/någons/Kalles mormor". If used alone, "min" is implied.
No, it isn't used that way. If you want to speak about someone no longer being 'with' us as in alive, we'd use med in Swedish too. Farmor är inte längre med oss. 'Grandmother is no longer with us' – this doesn't necessarily mean that she's dead, but it might.