Bonjour,
Réponse :
Note les cas où 's est un génitif.
Hello, I'm Marie. I live in Los Angeles. I live with my parents and my sister, Alice. We have a dog. In fact, it's Alice's dog, but I take care of him too. His name is Bin. Bin's a very cute dog. He's always sleeping or playing with us. I like Alice's dog a lot.
génitif: "Alice's dog" ( le chien d'Alice )
Les autres 's sont des contractions de "is" ( It's = It is // Bin's = Bin is // He's always sleeping = He is always sleeping )