Walls going up fast

Here I'm trying to watch and learn how to lay a brick from master builder Don Gerardo. The string shows him when the block is level. But he's too fast for me to figure out what he's doing. And the house already has almost half a wall around most sides.



All the wood everywhere is just there to support the strings used to guide building. I think it is the kind of professionalism that impresses people who see our constructor working.