At 11 months, Lucy knows the signs for "more" and "all done". She recognizes "eat" and will wave "bye bye" and say "ba ba" (usually once all chance of being seen doing so is over).
The funny thing is that she's learned the signs backwards, despite our best efforts. We consistently ask if she wants "more" and she responds signing "all done" and smiling, wiggling in her seat... Yesterday in the store she was strapped into the cart. She started to fuss and very clearly sign "more". I responded "more what?" before realizing she actually meant all done. I asked her if she was all done and signed it -- she started to wiggle and make her yes sound. This morning in the bath she wanted out and started signing "more". Anytime it's diaper time "more" makes an appearance now.
It's adorable! So much so that I almost don't correct her, but after all, we can't live opposites day forever... We just keep responding with the correct signs as our baby learns to communicate.