pick up on something

pick up on (something)

To detect or notice something; to become alert to or aware of something. There are a lot of mature jokes in this cartoon that I never picked up on as a kid. Did you pick up on the hostility between Jen and Tom? The cops picked up on his suspicious behavior right away.
See also: on, pick, up
Farlex Dictionary of Idioms.

pick up on something

in. to become alert to something; to take notice of something; to learn or catch on to something. She’s real sharp. She picks up on everything.
See also: on, pick, something, up
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • (mother) nature's (something)
  • a slew of (something)
  • a slue of (something)
  • a/the feel of (something)
  • (I) wouldn't (do something) if I were you
  • a straw will show which way the wind blows
  • a crack at (someone or something)
  • all right
  • (you) wanna make something of it?
  • all for the best