The other thing I thought I'd mention is that DD's development seems to happen in 'spurts' - she will grow a bit, do something new (like crawling, walking, become more coordinated with gross or fine motor skills, eg her last spurt a month or so ago she got better at balancing) and her language will step up a noticeable notch at the same time. Not sure if this is common, but that seems to be the way it happens with her.