Prosigns

First learn how the prosigns sound. The signs sound one at a time, with a pause after each. Type a sign with all its letters into one cell: SK is S and K. A sign counts once all its letters are typed. You start with two signs. When your accuracy reaches 90%, the next one is added: first it sounds a few times on its own. Once you know them all, the lesson on their meanings begins. Space skips a sign, Enter pauses.