"Thank you, I already ate."
Translation:Cảm ơn, tôi đã ăn rồi.
I have recently finished the Vietnamese lesson tree. I found two things missing that I very commonly encounter when in Vietnam (in the south):
1) Using rồi after the verb to indicate past tense. This is one of only a couple sentences that uses it this way in the whole lesson tree, though in Vietnam I encounter it very frequently, and much more frequently than I hear đã. For example: Tôi ăn rồi. Tôi đi rồi. Xong rồi.
2) Using đi after the verb to indicate imperative: ăn đi! Đi đi! Nói đi! I don't believe I encountered this once in any lesson, though I hear it used regularly every day in Vietnam.
I don't know if there is the possibility of adding new lesson sections at some point to the Vietnamese course, but these are both ones that I have found very common in Vietnam, that would be practical for users to learn and practice.