Why we need to give ba
How come you cant say women mai songgei ta yi ping meiguo pijiu ba?
That would be like "We buy give her a bottle of American beer". You can't just put a verb right after another in a sentence unless the first verb is a modal verb like "can".
I think after "mai" is noun
is it ok to say 我们买她一个美国白酒
Should be yi ping, not yi ge.
I think this implies you are buying 'her', you want to say you are buying 'x for her' or 'x to give to her'