What is the meaning of the idiomatic expression keen on eye. Please use in a sentence.
That is, of course, spot on. But how did you know the poster meant "keep an eye on"?Actually, it's more like watch carefully, as in
Ex: Please keep an eye on the kids while I am out.
Ex: Keep an eye on the kite and watch where it goes.
Ex: He's keeping an eye on my bags while I am in the restroom.