This is the 12909th most frequent Portuguese word.
és
"És" means "you are" (informal, singular).
The word "és" here is the second-person singular present tense of the verb "ser," used to describe an inherent characteristic.
Tu és muito simpático.
You are very kind.
In this sentence, "és" again indicates being or character, usually used for permanent or defining traits.
És o melhor jogador da equipe.
You are the best player on the team.
Here, "és" emphasizes a personal change, still applied to the verb "ser," signifying more permanent identity shifts.