ON/UPON
A combined preposition from up+on meaning on
The phone is upon the desk.
a)so as to touch a surface, also formal (upon)
There was something on/upon the table.
He jumped on/upon a horse.
She wrote upon the paper.
They live on/upon an island.
He got a blow on/upon his head.
b) supported by; hanging from, or fastened to,
He jumped on/upon one foot.
The ball is on/upon a string.
The wheels weren’t upon/on my car.
c) towards, to, in the direction of,
They marched on/upon Rome.
Make an attack upon/on the enemy.
She was on/upon my right.
The sun shines on/upon us.
d)Very near: The town was right on/upon the river.
My apartment is upon downtown Manhattan.
e) )By means of, They live on potatoes, or upon.
A car runs on/upon gas.
I’ve heard it upon/on the radio.
g)With the support of (money), try to live upon/on your own income.
He went around the world upon/on the money his aunt gave him.
h)As a member of, I serve on/upon a committee.
i)After expressions of money or effort, A tax on/upon income.
USAGE! A) A book on rabbits is a more scientific book than a book about rabbits.
b) Upon is sometimes more formal than on, but is standard in once upon a time, and upon my word.