'Depend upon' or 'depend on'

Question

Possible Duplicate:
Which phrase is correct: “dependent on” or “dependent upon”

Is there a difference between the usage of 'depend upon' and 'depend on' or is one considered improper usage?

Answer 1

NOAD:

The preposition ‘upon’ has the same core meaning as the preposition ‘on’. ‘Upon’ is sometimes more formal than ‘on’, however, and is preferred in the phrases: once upon a time and upon my word, and in uses such as: row upon row of seats and Christmas is almost upon us.

There is no other difference than that.

Answer 2

Grammatically there is no difference.

Style and usage? It is one of the "nicer" selections to have to make, as you can choose based on:

a: It is better to your ear,(1)

Or:

b: It is better targeted at your readership,

Or:

c: A combination of a and b.

(1) Italian has a word ("orecchiabile") for which the closest English translation is "palatable to the ear". Given that English is, shall we say, an "illegitimate" language, whose parentage is not strictly defined, I think that we should either steal the word (to add to the list of other words we've stolen), or create one that means the same thing.