the size of the production vocabulary ranges from about 50 to 550 words at the age of 2 years. influences on the rate of word learning, and thus on the wide range of vocabulary sizes of children of the same age, include the amount of speech children are exposed to by their caregivers as well as differences in how rich the vocabulary in the speech a child hears is. children also seem to build up their vocabulary faster if the speech they hear is related to their focus of attention more often. this would be the case if a caregiver talks about a ball the child is currently looking at.