In this lesson, the Verb Être= to be (present tense) with pronouns has been explained.
Je suis= I am
Tu es= You are
il/elle/on est= He/she/it is
nous sommes= we are
vous êtes= you are
ils/elles sont= They are
The tu and Vous refer to 'You', but tu is used in informal contexts while speaking to friends, and Vous is used in formal conversations.
E.g. Tu es mon ami. You are my friend.
Vous êtes mon professeur. You are my teacher.
Also, ils is used for a mixed group, whereas Elles is explicitly used for a feminine group.
For eg. Marie, John et Amy sont des étudiants. Ils sont gentils.
Marie, John and Amy are students. They are kind.
Tracy, Clara et Hima. Elles sont belles. Tracy, Clara and Hima. They are beautiful.
I hope you enjoyed this lesson. Please don't hesitate to ask me if you have doubts.