Problem with Genitive case sentence

[Ste-n-Dee]

Das ist das Haus der Großeltern should be translated as "This [or that] is the grandparents' house." Note the apostrophe after "grandparents", required in English to make the word possessive. Duo counts the translation as correct, but says the apostrophe is a typo.

Obviously, this needs to be corrected. But there is no way to report the error. The only error-reporting possibilities are that the audio is wrong, the dictionary hints are wrong, or the German sentence is unnatural.

As @domlecon pointed out in the discussion for that item, a language-learning site really needs to teach correct grammar, especially on an item like apostrophe use that so many native English speakers screw up.

[pentaan]

I agree.
Please, send a bug report via
https://support.duolingo.com/hc/en-us/articles/204728264-How-do-I-report-a-bug-

[mwbrand1]

Grandparents is the plural noun of grandparent. Grandparents' is the possessive form of the of the plural noun grandparents. For example:

My grandparents have a nice house. I enjoy staying at my grandparents' house.

In my opinion, you are correct and Duolingo should have accepted the apostrophe without complaint.

[BrianJConcannon]

That is correct

[lin.m.and.peggy]

Yeah, this does make sense. Even though some people here speak English and want to learn a new language, the website should not be saying things to us that are incorrect grammar in English, because we could be learning a tiny bit of bad information and we might not know it (NO OFFENSE WHATSOEVER TO DUOLINGO!!!!!!).

[lin.m.and.peggy]

Oh and yes I also agree with slamRN, idk if there should be an apostrophe or not, but I hope that it is not incorrect