Ответ:

Правильные предложения:

  1. His from Spain.    He's from Spain. ✓
  2. Her name’s Janet. ✓    Hers name’s Janet.
  3. There granny is a dentist.    Their granny is a dentist. ✓
  4. It’s her book. ✓    Its her book.
  5. We’re mum is beautiful.    Our mum is beautiful. ✓

Объяснение: he’s = he is, it’s = it is; her, their и our обозначают принадлежность. There означает «там», а we’re = «мы есть».