no indication whatsoever as to why it should be upo. Someone please explain.
Why does it have to be kati and not katikati?
I believe you can also use katikati since it also means between.
Why is "Mti kati ya nyumba na choo" not accepted?
sometimes "to be" is implied, but mostly in the present, non-locative sense (i.e. when you use "ni"). when there is location involved, you need to use one of the -mo, -po, -ko words