"yeah" vs. "yes"

I had a cooking teacher who whenever someone would respond "yeah" to her, she'd say something like "what happened to "yes" "yes" is acceptable, while "yeah" is not". What on Earth? "yeah" and "yes" mean the same thing. Either is fine. Why is she so stupid?

She just wanted to be a *****.

yeah is vulgar.

It's hardly vulgar. "Yeah" is colloquial while "yes" is considered more polite. At least in the South, you should say "yes ma'am" and "yes sir."

At least around here (southeastern Wisconsin), "yes" is a *very* strong affirmative, and is generally not used in everyday life unless one wants to give a markedly strong, definitive answer to someone or one is arguing with someone (think "yes, mother"). For most everyday purposes, people use "yeah" or "yah" [jaː], which are less marked than "yes", for most affirmative responses to people, even strong ones which are not definitive answers to questions. (Mind you that "yah" [jaː] is rather dialect-specific to the Upper Midwest, so I would not recommend you use it off-hand.) Hence it would be weird that your teacher would demand the use of "yes" all the time, as it really seems far too strong for normal everyday usage.

She was just being a prick. Some miserable old pathetic people will complain about 'yeah', but that's their issue. Not enough action probably.

Yeah is simply more casual, something you use outside of formal encounters. I say yeah to friends and co-workers, but usually not a boss or someone like that.

<<Why is she so stupid?>>
Why do you need to know? Maybe she's born that way. No need to worry. LOL

I don't know of any other language that has so many words for 'yes' as English!

1) yes
2) yea
3) aye
4) affirmative
5) yeah
6) yo (interjection which can mean 'yes')
7) yep
8) "yee-eh" (Kim Parker, do you wanna po'arty? : Yee-eh!
9) uh-huh

you teach er just wanted you to be polite and respectful. let her have that.

I recommend using "yes ma'am."