To have essential and current information; understand what is important: You look like a smart lad who knows the score (1940s+)
Also, know what’s what. Understand what is happening; be familiar with the real story or the full situation. For example, It will take the new legislators some time to know the score, or When it comes to teaching youngsters to read, Nell knows what’s what. The first expression, dating from about 1930, alludes to score as a tally of points in a game. The variant dates from about 1400.
- Know the time of day
verb phrase To be knowledgeable (1897+)
- Know what one can do with something
verb phrase (Variations: where one can put [or shove or stick or stuff] may replace what one can do with) To know that one’s offer, request, possession, etc, is held in extreme contempt •A euphemized way of saying that one can take something and stick it up his or her ass: I saw the contract, […]
- Know what one is talking about
verb phrase To be very knowledgeable •Often used in the negative, denoting speaking in ignorance: popped off without knowing what he was talking about (1920+)
- Know where one stands
1. Be aware of one’s position relative to others, or how one is regarded by others, as in I’d love to know where I stand with the new board. 2. Be aware of one’s own opinion or feelings about something, as in He knows where he stands on the issue of public housing.