What are the differences?

Guest   Fri May 09, 2008 8:58 am GMT
what are the differences between "knock at the door" and "knock on the door"?
guest   Fri May 09, 2008 2:51 pm GMT
"Knock at the door" means that you have heard a knock at the door (i.e. there is a knock at the door--someone is there knocking). It is locative in that "at the door" refers to a location.

"Knock on the door" is to physically hit the door with the knuckles--one is knocking upon the door itself.

One does not normally "knock at a door". In this phrase, 'knock' is a noun.

"Knock on the door"--'knock' is a verb.