someone else
compound.compound. A different person; not you, and not the person we are talking about right now.
compound. An indefinite pronoun phrase referring to an unspecified person other than the one already mentioned, implied, or present.
I think someone else should answer the phone.
If you don't want this last piece of cake, I'm sure someone else will eat it.
She lived in constant fear that her husband would leave her for someone else, a worry that consumed her thoughts.
The possessive form is 'someone else's', with the 's' at the very end.
Teach 'someone else', 'anyone else', and 'no one else' together as a set to establish the pattern of 'indefinite pronoun + else'.
This must be someone's else jacket.This must be someone else's jacket.The possessive marker 's' attaches to the end of the entire phrase 'someone else'.