Question

When do we use on and upon in a sentence?

For example, We agreed ______ a common plan.
--->Do we use on or upon

Answer 1

Answer:

upon is more formal than on.

=> On

Explanation:

we can use both on or upon here, but from my understanding, on would fit better.

Edit:

One more thing I would like to add is that upon is also used when talking about moving objects.

Example- The puppy jumped upon the mouse.

The puppy jumped on the table.

Answer 2

we use on.....

hope it helps