Im confused i think its broken

Shouldn't this simply allow for "ni he cha ma?" Or "he cha mam"

This is repeated twice in the question. Also, some chinese people would say "ni he bu he cha" as an informal way of saying it.

You in English can be plural - as such 妳们喝茶吗？should be accepted.

I typed this exact response but the program said it was incorrect?