My son is an incredibly verbal child. He could speak in sentences around 16 months old....granted, they were broken sentences, often like, "Mama, juice cup me!"
Well my daughter is 16 months old, and she doesn't say very many words. She says mama, dada or sometimes da, and bubba for her brother. She tries to say bye bye, ball, night night, and I love you...but I'm not sure anyone other than dh, my son and I would understand her.
I'm not really concerned at this point, because I know kids all develop at different paces. I can just really see the difference. But my dh is getting worried about it, so I was just curious as to when other babies started talking.
I will add that my dd is able to understand so much, too. She surprises us often with what she understands, she just can't say it herself.