"Do you see her dog?"
Translation:Siehst du ihren Hund?
ihere is not a German word. Ihre is the possessive for a grammatically female object, but der Hund is male, so it must be ihren.
Is -en used whenever the noun that the word applies to is grammatically masculine? And does that mean that ihren would be for masculine nouns, ihre would be for feminine nouns, and ihr would be for nutter nouns?
For the accusative case, yes. The other cases have different endings.
I just learned the rules behind the cases, so i get it now. Thank you anyway!
sein is nominative, but you need an accusative here, that would be seinen or ihren, but as it says her, it can only be ihren. Seinen is his.
Isn't there also a specific word for a female dog in English? In Germany Hund is the default if you don't know or don't need to specify the gender.
Sure, it's just a bit unusual. I always had dogs with my family and we just referred to them as der Hund or die Hunde if we didn't use the names. All of them were females. I just use Hündin in the special case when she's in heat and I encounter another dog ( and it's owner...) that might be male. Or if someone asks explicitly.
Proper yes/no questions always start with the finite verb, then subject, then object. So for the given sentence, there is no chance to vary the order.