Yo estoy
Tu estas
El/ella/Ud esta
Nosotros estamos
ellos/ellas/Uds estan
To remember the use of the verb remember this simple scene:
I met you in an occasion, you were happy, in good health and well dressed.
Ester can be used for all above conditions: location, health, changing mood or condition and opnion regarding taste and appearance.
Examples:
Estoy en la clase
I am in the class
Estamos bien, gracias
We are well, thank you
Estoy feliz
I am happy
La comida esta buena
the meal tastes good
