on the uptake

quick on the uptake

Able to grasp or understand something very quickly and easily. She's pretty quick on the uptake, so I'm sure she'll figure out the directions you left her. This is a fast-paced environment, so you'll need to be quick on the uptake from the moment you start the job.
See also: on, quick, uptake
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

on the uptake

In understanding or comprehension. This term is most often put as quick on the uptake, for readily understanding something, and slow on the uptake, for being slow to comprehend. For example, Shirley will have no trouble learning that new computer program-she's very quick on the uptake . It alludes to absorbing ("taking up") information. [Early 1800s]
See also: on, uptake
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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References in classic literature ?
"And in the South Seas garnered a better vocabulary from the lexicon of Love," Percival was quick on the uptake.