When using soba, no need to use "watashi no" as soba already implies ones own grandmother and also no need for desu at the end depending on formality.
*Sobo, please do not eat your grandmother
yeahhh, and if you wanna refer to someone else's grandmother you would use 彼のお婆さん (obāsan) right?
Yes, but お婆さん is actually used for "old woman", while お祖母さん is used for "grandmother", but really you usually just write it in hiragana: おばあさん
precisely. by the way does it make sense if i there's a ん at the end?
"Soba" means noodle but it is a common mistake and is sometimes used as a joke. "Sobo" was used in my sentence for grandmother.
Is そぼの耳がわるいです incorrect? If so, why?
Duo accepts this
It is correct. Duolingo is just weird.
Weird that you get incorrect marks if you don't add "desu" at the end.
depends of the phrases sometimes it's ok if you omit it, sometimes it's not. Sometimes duo wants you to use the plain form, sometimes the polite form ¯_(ツ)_/¯
why ga here?
Seems a little rude when put this way?
It seems it to us, but people are always asking me 目が悪い (me ga warui?), so I think using "warui" is a normal way to express that someone can't hear well or can't see well.
I think "うちの" should be taught instead of "わたしの" for family. I wouldn't even use "わたしの" for my cat because it's a part of my "home base"