For awhile now, Alex has been saying "mamamamamama" sometimes when he's upset. It's been sort of unclear whether he actually meant "mama" or not.

But, just a few days ago, we were at the in-laws' house for dinner and my mother-in-law was holding him and playing with him. She walked up next to me and he smiled at me, put his arms out to me, and said "Mama!". :) :) :)

Since then, he's been doing it more often, when happy as well as when he's upset.