Well, I can't say this is an easy question. I just use this word and may never think about its meaning if you didn't ask. :) When "mà" stands at the end of a sentence, it has explaining function. A: Sao anh không đi làm? - Why don't you go to work? B: Hôm nay là chủ nhật mà. - It's Sunday today. (that's why I don't need to work) When something happens like what somebody predicted or warned before, then he/she uses "mà" to emphasize what he already predicted/warned. A: Con bị cảm lạnh rồi. - I've caught a cold. B: Mẹ đã bảo rồi mà. Đáng lẽ con phải mặc áo ấm trước khi ra ngoài chứ. - I told you already. You should have dressed warmly before going out. Peter nói: "Tớ biết mà!" - "I knew it!", said Peter. Hope this helps.

It's just a linking word. Actually it has no particular meaning

im vietnamese, in my thought it's a linking word in a sentence, so cant cut the meaning without real