There are some phrases with the sense "to be very clever":
To have a clear head;
To have a good head on one's shoulders;
To be a bright spark;
To have one's head screwed on;
To be as bright as a button;
To be as clever as a cartload of monkeys;
To be quick in the uptake.
Do you use/ know other phrases with the same sense?
Thanks for all your replies!
In the UK, at least, these expressions are common -
'Swot' - this is meant sarcastically
'Brainbox' - this is a 'kinder' expression, and is not meant sarcastically
smart as a whip
I head the phrase: "smart a-s-s" in a movie!