at about 5 months, but not by the half-rolling sort of way babies normally do. She would push her upper body with her arms and scramble her legs forward until they were forward of her hands and plop down like a monkey. She would then usually topple over until she was almost 7 months old. She babbled incessantly, played with noises and was intensely curious about sounds. She spoke well formed words before she was a year old and had an amazing grasp of Japanese and English grammar before she was 2 (I live in Japan, hence the two language thing).
Second daughter: She didn't care much about sitting up for a very long time, and only crawled a little bit. Instead she would look at where she wantedto go and roll there. Which was hilarious, but a little alarming -- until my mother told me I used to do the exact same thing, and so did my brother's daughter in Texas. She wasn't interested in sounds at all. She made almost no babbling noises, very rarely vocalized anything, and didn't even cry much. When she was a little over a year old, though, it was clear that she understood what we were talking about when we addressed her -- but never spoke. In contrast to the first daughter we were a little worried, but figured it would turn out however it would turn out. She didn't say much until she was about 20 months old. Once she turned two, she just suddenly started saying full