on (in various senses), or up and on: on and upon are generally interchangeable, the choice being governed by idiom, sentence rhythm, etc.
Origin of uponMiddle English from up, up + on, on, probably influenced, influence by Old Norse upp á ( from upp, upward + á, on)
- on: used only for completing a verb: a canvas not painted upon
- Obs. on it; on one's person
- Obs. thereupon; thereafter
On: The leaves are scattered upon the grass. He put the book upon the table. Upon hearing the news, we all cheered.
A somewhat elevated word; the simpler, more general term on is generally interchangeable, and more common in casual American speech. In poetic or legal contexts, upon is common.
- Being the target of an action.
- He was set upon by the agitated dogs
- Incidental to a specified point in time or order of action; usually combined with here-, there- or where-.
- The clock struck noon, whereupon the students proceeded to lunch.