"She was finishing her work."
Translation:Ŝi estis finanta sian laboron.
A complex verb form, "estis finanta," but "finanta" is written like an adjective, though it works like the simpler verb "finas" by requiring an accusative object of "sian laboron." Though a form of 'to be' is involved, "estis," the accusative form of the object is nonetheless required. Okay, I'll run with it, but a better explanation of the grammar would be very welcome.