"Below the library there is a coffee shop."
Wouldn't it also be correct to say 图书馆下面有咖啡馆 (minus the 的)? I got marked wrong
Not necessary unless the number is specified. Although it is likely to be 1 café, more is also possible.
Good question! Such as 一家?
It's still being marked wrong without 的。的isnot required. Also "a coffee bar" indicates only one, so 一家咖啡馆 I think is correct.