I generally keep any screening or observations to myself till a child is two. That is the age at which many doctors will start to rethink their advice of don't worry he will grow out of it or don't worry the skill will come. Around two is when we should be seeing mastery of skills that were emerging and being practiced. Late walkers who barely toddled at 18 months should be walking normally by age 2 or saying at least a certain number of words whether been doing it for months or just learned them last week. While all children develop at different rates especially in the infant/toddler years there is an expected baseline mastery that should be there by age 2 so the child can move from toddlerhood into preschool.
