Seconding this. In notes during an earlier lesson (I apologize, but I do not know which one) it said to assume "the" unless "một" was present, but that has been inconsistent. Perhaps that should be changed to instruct us to always use "a" when translating "một," but that "a" can also be implied by context?
I'm enjoying these lessons and learning so much, and I really appreciate all of the work that the team put into creating the Vietnamese course, so please understand that this is a minor criticism. However, the inconsistencies are the hardest part of this course! I know it's still in beta and there is a lot to do. Thank you so much for taking the time to create it. But a little more consistency in instructions and examples would go a long way toward making learning Vietnamese easier.