15 months

Mastered
• Plays with ball
• Uses three words regularly
• Walks backward
He's got the ball thing down - he's got a great arm and loves to throw them to you or carry them around in his hand if they are the right size (like a golf ball.)
He uses mama, dada, hi, bye, duck and dog usually on a daily basis. 
As for walking backwards... hmm... I can't say that I've seen him do that. I mean he's stepped backwards to get out of the way if I'm opening the fridge or something if that's what they are talking about but if they mean more than two or so steps I can't say that I've seen him walk backwards.


Emerging
• Scribbles with a crayon
• Runs
• Adopts "no" as his favorite word
He can and does enjoy scribbling with a crayon - usually copying sister coloring. 
He can run and has gotten much better about not going to fast for his feet so that he trips but it still happens on occasion. 
So far 'no' is not even in his vocabulary. He does know what it means but we don't always use the word 'no' sometime we interchange with danger or simple redirection without using the word 'no.' 

Advanced
• "Helps" around the house
• Puts his fingers to his mouth and says "shhh"
He does help around the house. He loves to shut the washer and dryer doors - maybe a little too much as he tries to do it before I'm done switching the laundry. He will do his best to put something in the washer or dryer if I give it to him. He will help clean up when we are picking up legos or crayons and put them in their container. He's getting to be a good little helper! 
He doesn't say "shh" but that's not something we do often around here so it's not something I would have expected him to pick up. 


Vocabulary list: 
mama
dada
dog 
duck
helicopter/car noises


recent additions (as of 8/23) that I think I've heard him say recently but can't be certain of just yet:  
frog 
ball