thank you。but there is exactly something unexpected about the “no matter and doesnt matter”. let me show a bit of the context where i got this confusion : They may be voluble ，vociferous ，garrulous，verbose，but never inarticulate，taciturn，or laconic. “No matter”. It' s the quantity and continuity that are most conspicuous. so，“no matter ” here should also mean “its not important” ，which i guess should be the same as “doesnt matter”。 how do you think of It？ hoping for more of your opinion and guidance～thanks～

oh, and the first two sentences are a bit different. sometimes the first one means that I don't worry, and the second one means that you shouldn't worry.

Hi, The first two are synonymous. but the second group is a bit different. "no matter" is used in expressions like: No matter how hard I tried to explain the difference between the two sentences, I couldn't make myself clear. ;) but "doesn't matter" means "isn't important"