For the second part, let me emphasize from RandomQuotes' post that の was left in the sentences.
Think of it kind of like saying "Who's is it?" instead of "Who's <thing> is it?"; you don't leave out the possessive bit, just the part that's known.
RandomQuotes Wrote:A: だれのですか。
B: 私のです。
Think of it kind of like saying "Who's is it?" instead of "Who's <thing> is it?"; you don't leave out the possessive bit, just the part that's known.
Edited: 2016-01-24, 1:36 am