What's the difference between: "look down ON" x "look down UPON" someone ?
Do I use "by" too?

She was looked down upon by the manager.
He was looked down on by his colleagues.

Question

What's the difference between: "look down ON" x "look down UPON" someone ?
Do I use "by" too?

She was looked down upon by the manager.
He was looked down on by his colleagues.

Answer

The meaning is basically the same.
You can use either.

Answer

They are both correct and equivalent.

Yes, "by" is the correct preposition.

Answer

There is no difference in meaning but "upon" is the better choice.

"Upon" means on from above. "On" means the same thing, but "from above" makes it more descriptive. It is more clear and emphatic.