I don't know what changed.  Whatever it was it started 2-3 weeks ago.  My two almost three year old has a consta-whine.  She can turn it on at the drop of a hat for no reason at all.  It's almost as if the more her vocabulary grows the less she uses it and just whines for what she wants.  There aren't even words mixed in, it's just a low level "ahhhhhhhhhhhhhhhh........."  The more I ask her to use her words or try to guess what she wants the more she mumbles and whines.

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