were doing
Sigan con lo que estaban haciendo.
Keep doing what you were doing.
Estaban haciendo un puente a mi coche cuando los sorprendí.
They were hot-wiring my car when I surprised them.
Todos en la sala estaban haciendo la misma cosa.
Everyone in the room was doing the same thing.
Vuelvan a lo que estaban haciendo.
Go back to what you were doing.