"Some/this man came up to me and said..."

[clawgrip]

I always assumed "some guy" or "some woman" was just a gender-specified version of "somebody" or "someone"; those are pretty universal terms across English dialects, aren't they? Maybe a bit perjorative, but "that woman", "that man", "those people" are also considered mildly perjorative in my dialect.(northeastern US, specifically Erie PA)

I don't think they are just gender-specific versions of someone. You could simply say "a man" or "a woman". The use of "some" in place of "a" seems to me to suggest what the OP said: that it is a random, unknown, unexpected thing, possibly with a pejorative connotation.

[sunandshadow]

I always assumed "some guy" or "some woman" was just a gender-specified version of "somebody" or "someone"; those are pretty universal terms across English dialects, aren't they? Maybe a bit perjorative, but "that woman", "that man", "those people" are also considered mildly perjorative in my dialect.(northeastern US, specifically Erie PA)

I don't think they are just gender-specific versions of someone. You could simply say "a man" or "a woman". The use of "some" in place of "a" seems to me to suggest what the OP said: that it is a random, unknown, unexpected thing, possibly with a pejorative connotation.

Somebody or someone is always a random, unknown person, isn't it? (Or unimportant that it's known because it's random). Like, "Somebody stole my car!" vs. "Some guy stole my car!" The only difference seems to me to be that in the second case a witness must have been there to identify the thief's gender.

[clawgrip]

Semantically they are basically the same, but pragmatically they are not.

Compare:

Someone sitting beside me on the train asked me a question.
A woman sitting beside me on the train asked me a question.
Some woman sitting beside me on the train asked me a question.

Surely you recognize the difference in attitude of the speaker in the last sentence. It seems to be showing at least some degree of annoyance or surprise that a random person I had no intention of talking to ended up interacting with me.

[sunandshadow]

Semantically they are basically the same, but pragmatically they are not.

Compare:

Someone sitting beside me on the train asked me a question.
A woman sitting beside me on the train asked me a question.
Some woman sitting beside me on the train asked me a question.

Surely you recognize the difference in attitude of the speaker in the last sentence. It seems to be showing at least some degree of annoyance or surprise that a random person I had no intention of talking to ended up interacting with me.

For me it's a scale:
(most neutral) a woman<->someone/a random woman<->some woman/one of those women/that kind of woman (most implied surprise or disapproval)
It can go the other way too:
a woman <-> a lady <-> a lovely/nice/friendly woman