Hi E.,
While other kids my sons age (18 mo at the time) were speaking clearly, my son hardly ever spoke and when he did, he babbled, He was a quiet baby, however, when he turned 2 (and maybe a couple months), it was like someone turned on a clear-talking switch, he spoke full sentences, like a little adult and never baby-talk, I read somewhere that some kids just observe words and sentences, practice them in their head, then, when there comfortable, start talking. I did, however, worry and follow the instructions of talking about everything I was doing, at grocery stores I'd talk to him like I was shopping for a blind person, "Do we need Catsup? Lets see what kinds there are, Hinds, Hunts, etc" I did that with everything all day, I guess it worked, he's 11 yrs old and still won't stop talking (lol). Good luck