1) old, older, the oldest, my older brother, my old friend, the longest, shorter, happy, happier, the happiest, the best, longer, worse, better, warmer, her best friend, her youngest son, his oldest son
2) She, he and I... He and she... He works... It is... She is a teacher... He and you...
3) 1. your 2. his 3. his 4. their 5. our 6. my 7. your 8. her