I've come across this conversation exchange in the transcript of a textbook:
(the speakers are discussing that a friend of theirs has been dismissed because he was sending personal emails from the company's computer)
Laura: That's a bit unfair, isn't it?
Dom: You say that, but actually what happened to him was he visited …
I think I can guess what the meaning of "you say that" is: "you say that because you don't know the whole truth", but I'd never heard that phrase. I'm looking it up in different dictionaries but I can't find it.
Is it an usual phrase to indicate that somebody's guess is wrong?
Best Answer
Yes - You say that, but [some refutation or caveat] is idiomatically commonplace for many native speakers, in response to an assertion they disagree with.
It's nearly always used in a context where although the speaker doesn't fully agree with the preceding assertion, he recognizes that there's some truth in it.
In fact, you'll often hear You could say that, but..., which more explicitly acknowledges that the assertion is at least "credible", even if it's not completely accurate. Note that in this usage, you = one, anybody, not necessarily the person being addressed (i.e. - what it amounts to is something like It wouldn't be ridiculous for you/someone to say that, but it's not entirely true).
Also note that if the personal pronoun is stressed (You say that, but...), the implied meaning shifts significantly. This form almost always occurs in contexts where the speaker completely disagrees; he intends to dismiss your opinion on the grounds that you're ignorant or biased, and/or to cite other sources more authoritative than you to refute what you said.