pick up on
phrasal verbpick up on something
- to notice something and perhaps react to it
- She failed to pick up on the humour in his remark.
- to return to a point that has already been mentioned or discussed
- If I could just pick up on a question you raised earlier.
pick somebody up on something
- to mention something that somebody has said or done that you think is wrong
- I knew he would pick me up on that slip sooner or later.