17. USING SER - USANDO SER
I am - yo soy
you are (informal) - tú eres
you are (formal) - usted es
he is - él es
she is - ella es
we are - nosotros somos
we are - nosotros somos
they are - ellos son  
you all are - ustedes son

 I am a student - yo soy estudiante
you are smart - tú eres inteligente
he is from Mexico - él es de México 
we are Argentinian - nosotros somos argentinos
you all are friends - ustedes son amigos
they are artists - ellos son artistas
the chair is black - la silla es negra
it is three o'clock - son las tres
the book is long - el libro es largo 
she is a teacher - ella es profesora
he is handsome - él es guapo