Someone and somebody

[indian]

Which on do you use when?

[jno]

I think it's just a matter of taste, indian; and the same for nobody/no-one. I know people who just can't abide saying 'somebody' at any time. But it may be when you're trying to write elegantly that one word or the other simply sounds better (perhaps because 2 syllables, or 3, suits the rhythm of the sentence better).