Why could it only be we, doesn't the -iz suffix refer to we, them, and the plural you?
Not at all :) It only refers to "we" actually.
You plural -- (Siz) içersiniz
They -- Onlar içer(ler) or just "içerler."
Why does duolingo insist on having the word "the" before tea. Not just in this sentence, but for everything in this lesson. I thought there was no Turkish equivalent to "the". It marked "We drink this and tea" wrong for me, but the word "the" isn't needed in the sentence. Or am I just tripping?
What would be the translation in this sentence please Bu ve çay içeriz Thx
It wouldn't make any sense. "Bu" will always be in the accusative case when it is a direct object :)
I just said it above. When "bu" is a direct object, it will always take the accusative case. Please read the comments before posting and prevent clutter :)