An invisible man is here to see you
Nurse: Doctor, there is an invisible man in your waiting room.

Doctor: Tell him I can't see him now. Next.

A succession of generations
The village blacksmith finally found an apprentice willing to work hard at low pay for long hours. The blacksmith immediately began his instructions to the lad, "When I take the shoe out of the fire, I'll lay it on the anvil; and when I nod my head, you hit it with this hammer." The apprentice did just as he told. Now he's the village blacksmith.