on the ball
idiomPart ofball
on the ball — idiom
1. quick to notice, understand, or react to what is happening; alert and competent.
1.idiom
Definition
quick to notice, understand, or react to what is happening; alert and competent.
Example
The new receptionist is really on the ball — she answers every email within minutes.
You need to be on the ball during the morning rush at the café.