So, what is the child doing motorically at 1 1/2 years to 2 year, during the period of Anticipatory Language?
If one notes the context in which the words are uttered, it will become apparent that the same word may be conveying different messages at different times.
"Baba" on one occasion may mean, "Bring me a bottle." On another occasion, it may mean, "That is my bottle." And still on another it may mean, "That is mine--don't touch." It might even mean, "That is white like my bottle."
These are in essence, one word or Holophrastic sentences. They have within them in the deep structure, the implicit beginning of grammatical functions including, for example, verb categories, nouns and the possessive case.
Motorically, the child is now walking, albeit with a somewhat stiff gait. He/she is beginning to build towers two blocks high, and shows some preference for one hand or the other.