Hi! Could I ask you this question?
Practical English Usage (fourth ediction) says that the preposition "at" following the verb "look" is often dropped before a wh-clause.
(1) Look (at) what you've done!
I was wondering whether there is any semantic difference when the preposition is present/absent. I was also wondering whether the preposition can appear after "look" in the following sentences (taken from Practical English Usage):
(2) Look who's here!
(3) Look where you're going.
I would appreciate your comments!