"I love him because he is honest."
Translation:Tôi yêu anh ấy vì anh ấy trung thực.
I've asked my vn teacher on the last weekend. He says there's no interpretation or evaluation for the different translations of "because". So normally they should accept "tại vì", "bởi vì" and just "vì" in this case. Maybe there is a case where this is incorrect, so I'd just like to know it. Thanks in advance, to the mods as well.