Estás bien.
Estoy bien = I'm OK/doing fine etc.
OK, mañana
ok
OK, why?
"Bueno."
¿Cómo estàs ustedes? is how you say "how are you doing everyone?" in spanish.
ok
Estas bien?
No estás bien
In English, "ok pero quien era" translates to "ok but who was it."
"Hello, how are you doing?" in Spanish is "Hola, ¿cómo estás?".
It is Spanish for " what will be " ... OK that is a unsure answer but it is Spanish.