Ds is 19 months, and is just starting to say Mama in direct reference to me. He 'talks' all the time, but we have no idea what he is saying! I just noticed though that he makes sounds for certain objects - like he was trying to climb on his highchair the other day, and I realized he was making a "hych" sound. Sometimes when I hand him something he makes a "tnk" sound for thank you. He's been doing this for a little while, but it was just so subtle that I never made the connection before.
But in general, he is not talking. I'm not worried, as he understands really complex sentences and directions.