1. Tu et Vous
Grammaire: page 49

2. In French, there are 2 ways to say you :
Tu is informal & singular.
Vous is formal & singular, or may be used to address more than one person informally.

3. Use tu when talking to one friend, one person your own age, or to a family member.
Talking to your friend, Paul:
Talking to your mom:
Paul, tu es libre maintenant?
Maman, tu es contente?

4. Use vous when talking to 2 or more people:
Talking to your friends Paul and Marie:
Paul et Marie, vous êtes occupés maintenant?

5. Use vous when talking to an older person, an acquaintance, or to anyone whom you wish to show respect:
Talking to your teacher:
Madame Baldwin, vous êtes occupée?