What’s the rude way to say “You just said something that I already know”? For example, two people (John and Paul) on a bus are arguing. John says, “You were touching my leg.” Paul replies, “I didn’t know that.” John says, “Now you do.” Of course Paul knows that now, because John just told him in his first sentence; so what John says doesn’t add any new information to the conversation. It’s purely meant to anger Paul. In my native language, there’s a rude word to rebuke people when they say such things. It means “what you said is superfluous”, “you needn’t say that” and “that’s what I already know so you wasted your breath” in a rude way. In English I know we can say “needless to say”, “it goes without saying” or “you’re stating the obvious”, but are they rude enough? Is there a ruder way to convey that meaning? Thank you.
no shit, Sherlock
Said humorously to express the view that someone is stating something that is completely obvious.
Origin 1970s with ironic reference to the famously perceptive fictional detective Sherlock Holmes.
There are a few worrying findings: the first is that congestion causes stress (no shit, Sherlock) and the second says that traffic jams may cause brain damage Lexico