<prompt> In a child, one should be worried ifStammering occurs at 3 yearsLack of Toilet control at 2.5 yearsTeeth do not erupt by 11 monthsSocial smile absent by 10 weeks  <response>: .ge 2 months 3 months 6 months 9 months 12 months 15 months 18 months 2 years 3 years 4 years 5 years Milestone . . mile after being talked to social smile s ther anticipates feeds Recognizes mo . t angers stranger anxiety Recognizes s r waves bye bye . h Called plays simple ball game comes w en Jargon . Copies parents in task .g. sweeping f food drink toilet; pulls people to Asks or show toys Shares toys; knows full name and gender Plays cooperatively in a group; goes to toilet alone Helps in household tasks, dresses and undress 