Babies and children develop at their own pace, so it's impossible to tell exactly when your child will learn a given skill. The developmental milestones listed below will give you a general idea of the changes you can expect, but don't be alarmed if your own childs development takes a slightly different course.
Important Milestones: By the End of Three Years
(36 Months)



Social
  • Imitates adults and playmates
  • Spontaneously shows affection for familiar playmates
  • Can take turns in games
  • Understands concept of "mine" and "his/hers"

Emotional
  • Expresses affection openly
  • Expresses a wide range of emotions
  • By 3, separates easily from parents
  • Objects to major changes in routine

Cognitive
  • Makes mechanical toys work
  • Matches an object in her hand or room to a picture in a book
  • Plays make-believe with dolls, animals, and people
  • Sorts objects by shape and color
  • Completes puzzles with three or four pieces
  • Understands concept of "two"

Language
  • Follows a two- or three-part command
  • Recognizes and identifies almost all common objects and pictures
  • Understands most sentences
  • Understands placement in space ("on," "in," "under")
  • Uses 4- to 5-word sentences
  • Can say name, age, and sex
  • Uses pronouns (I, you, me, we, they) and some plurals (cars, dogs, cats)
  • Strangers can understand most of her words

Movement
  • Climbs well
  • Walks up and down stairs, alternating feet (one foot per stair step)
  • Kicks ball
  • Runs easily
  • Pedals tricycle
  • Bends over easily without falling

Hand and Finger Skills
  • Makes up-and-down, side-to-side, and circular lines with pencil or crayon
  • Turns book pages one at a time
  • Builds a tower of more than six blocks
  • Holds a pencil in writing position
  • Screws and unscrews jar lids, nuts, and bolts
  • Turns rotating handles

Developmental Health Watch
  • Frequent falling and difficulty with stairs
  • Persistent drooling or very unclear speech
  • Cannot build a tower of more than four blocks
  • Difficulty manipulating small objects
  • Cannot copy a circle by age 3
  • Cannot communicate in short phrases
  • No involvement in "pretend" play
  • Does not understand simple instructions
  • Little interest in other children
  • Extreme difficulty separating from mother or primary caregiver
  • Poor eye contact
  • Limited interest in toys
  • Experiences a dramatic loss of skills he or she once had




Content source: Division of Birth Defects, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention