Why is האם זו העניבה שלך an answer? זו doesn't mean "this," does it?
It does, זו and זאת are synonyms.
What about ?העניבה זאת שלך
Doesn't work. If you're trying to say "is this tie yours?" you would say "העניבה הזאת שלך"
Why not: זאת עניבתך
Because suffixes are not used in this course, with a few exceptions, because they are used rarely in everyday language.
I have just studied a whole skill on suffixes, so I decided to use one :) Good to know that they are rarely used in everyday life. The only problem is to know in which tasks Duolingo accepts/requires them, and in which not.
Why zu haaniva shela is wrong?
Zo זו is probably not in the system. Otherwise it should work. Also, it's שלך shelcha, not shela (maybe that was the mistake if you wrote שלה)
Placement of words and blank is incorrect!! Goes left to right!!