BB signed her first full sentence yesterday: Where, Bird, Swing.
This actually made perfect sense. When we were at the farmer's market on Wednesday, BJ wanted to get something from the balloon man, and he chose "the bird on a swing." BB was asking about the location of her brother's balloon animal. (It was in the next room.)
Recently she has added "music" and "stop" to her signing vocabulary. "Stop" has two meanings: the obvious one, and also the children's book Trashy Town, which is one of BB's favorites. It uses "STOP!" as a refrain. Last night, I thought she was asking me to stop doing something, when in fact she was asking me to find that book and read it to her. It's so gratifying to figure these things out!