I often hear on TVB shows that people say 最多 in a context when they mean to say, "at the very least?" For instance, something like, "At the very least, I'll take you to dinner tomorrow for being late."
Why is this?
Consider it this way: If your offer and his expectation from you are at two opposite ends, then the most you can offer only meets the least he has expected, or even less.
So the perspective(point of view) affects the use of "most" and "least" -- quite subtle. To make a specific case clear, we need the vivid context.
This heavily depends on the situation and the tone of the speaker. But in general, the speaker is either asking for something/help, or willing to gift something to listener because listener is unpleasant.
It is not like
"I will only treat you dinner tomorrow at most", but
"I will treat you a dinner tomorrow, please do me a favor", or
"You look sad, I could treat you a dinner tomorrow".
I just found out an easy way to distinguish between them, is to listen if it is "我最多" or "最多我":
I could only treat you a dinner at most.
I will treat you a dinner tomorrow~
The most difficult thing in Cantonese is the emotional particles. Most of the sentences will include particles at the end and represent our attitude and emotion. There are a lot of them but they are only 1-3 characters so it is very easy to be confused. I suggest you to ask your Hong Konger friends about it or you can ask me too.
In Vietnamese, 最多 means at most, upper limit. And 最少 means at least. Not sure why in Cantonese.
I think you maybe have understanding issues.
最多 does not mean "at least". It means at the most.
I honestly have no idea why someone who provided you the best answer from user3992 is having negative points but his answer is correct.
It means "at most". Cause I believe Chinese people's nature is to do as less as possible, so we say
A: 你可以帮我做完这件事无? B: 可以! 我做这件事可以拿到乜嘢? A: 最多，我可以请你吃饭. A: Can you help me with something? B: What will I get out of this? A: I can, at most, treat you to dinner.
"At least" in contrast we use for if someone declines our favor.
A: 你帮我好多, 我可以用乜嘢方法报答你无? B: 毋使! A: 至少 ，我应该请你吃饭. A: You helped me so much, how can I repay you? B: No need to. A: At the very least, I should treat you to dinner.
Edit:It's a perspective problem. It's usually from the speaker's perspective, not the listener's.