If you are talking about the corner of a page, please see
What is the correct preposition?
If you are talking about the corner of a room, in makes sense, the others don't.
If you are talking about the corner of a street, on or at make sense, in doesn't.
On the other hand, others may have completely different views.
Could you clarify what kind of corner you are interested in?
I was talking about the corner of a street. So, can I say there was a suspicious-looking guy standing at/on the corner?
In present tense, 'on the corner' is most common in Australia, and in past tense 'at the corner'.
Never said it did. I just said it was most common. I hear both versions, just that one version is more common. For one version to be in more common use isn't unusual (and the version can differ from region to region and country to country)Sorry, but not in my neck of the woods.
The use of at, in, or on has nothing whatsover to do with verb tense
We 'meet at' a particular location because that's the collocation that's natural, not because we're mobile.
The image is of a room. The corners of a room can be dark and neglected. Important things take places of honor in a room where everyone can see them. Something that is pushed to the corners of a room is unimportant. Does that help?