Does anyone else know anything about using or not using ( yeah but )? To me it seems that in certain situations yeah but is an appropriate response.
My friend really really disagrees. He says that by saying yeah you are agreeing, then the but contradicts your agreement, putting people on the defensive.
Any and all thoughts are appreciated. Thank you  George Shaffer
Strictly speaking, agreement is already implied in 'but,'  otherwise, you would have just said 'No.'  'But' is pretty close to  'Although,'  both an expression of acknowledgement, before you turn around to qualify it.  So the 'Yeah' in front does sound a little extraneous to me.
I tend to agree with RobertB. The "Yeah" or "Yes" preceding "but" is certainly not necessary, and is implied as acknowledgment when you start with "But" or "Although" or "Nonetheless" or "However".
However, in the spoken language, starting with "Yeah, but" or "Yes, but" is so common that you shouldn't be getting corrected for using it. And that construction is NOT at all contradictory, as your friend claims.
In formal writing it should never be used, except possibly when answering the writer's own rhetorical question.
jaimeyeahbut said
My friend really really disagrees. He says that by saying yeah you are agreeing, then the but contradicts your agreement, putting people on the defensive.
Yeah does mean agreement but not necessarily total agreement. But comes along to mention some things that you may disagree about the premise.
I agree that this phrase can be meaningful and useful but I have heard some who look for anything to disagree about and overuse the phrase simply to start an argument. Could your friend be seeing this in you?
I also see it as common and acceptable. The yeah or yes serves to underscore the possible agreement. If agreement is clearly not implied, then the yeah or yes simply concedes the validity of the opposing point. In the case of disagreement it is softer then simply starting with but.
A: I think John was in the wrong.
B: But he was misled by Pat. [adding nuance; yeah, agreement may be implied, but complete disagreement is also possible]
*
B: Yeah, but he was misled by Pat. [adding nuance; agreement is more likely]
===
A: I think we should get gas before we head out.
B: But gas is cheaper if we wait till we're in New Jersey. [no agreement implied; stating an opposing point]
*
B: Yeah, but gas is cheaper if we wait till we're in New Jersey. [yeah affirms speaker A's opinion before making an opposing point.]