So "tôi đã no" doesn't mean 'I was full"? How does Vietnamese differentiate between being full now and being full in the past. i.e. if I'm telling a story and to conclude I say 'Tôi đã không đói, tôi đã no' (I was not hungry, I was full). Could this be interpreted as 'I'm not hungry, I'm full'. Anyway, I've a feeling that, given the vietnamese hospitality, the food will continue to be offered, whatever my explanation is (for being full).
you would used time markers to position the story in the timeline.
"hôm qua khi đi học về, tôi ghé siêu thị mua ba lý kem ăn dọc đường. về tới nhà, tôi chẳng muốn ăn cơm nữa vì tôi đã no quá rồi."
"yesterday on my way back from school, I stopped by the supermarket to buy three cups of ice cream that I would eat on the road. when I arrived home, I couldn't eat dinner anymore because I was so full."
"ua, nhiều món quá! tí nữa, no quá, làm sao chạy xe đạp về?!"
"wow so much food! how am I supposed to ride my bike home later after eating that much?! (okay I'm just loosely translating here, because "when I will be so full" sounds a little funny)
Bro, In English, always 'i am', never 'i just..', (unless you want to say you just finished doing something) so 'i am just...' is correct. You used 'i am' correctly everywhere else. actually, I keep using 'la' in vietnamese when it's not needed. Let me check, 'toi an cơm' is correct (excuse my writing), 'toi la an cơm' is incorrect?. Or do i say 'toi dang an cơm' if i want to say 'i am eating rice'
rather than a regional thing, I would say it has more to do circumstances and formality. "no rồi" is usually said as an exclamation, kind of "woah, I ate well, I'm full.." however it is probably not recommended to say it to your elders or hosts when they are trying to serve some more food, as you might sound a little rude. it is then better using a full sentence like "tôi no rồi", "con no rồi", "cháu no rồi", etc.