can put objects together, take them apart; fit large pegs into pegboard. begins to use objects for purposes other than intended (may push a block around as a boat). does simple classification tasks based on single dimension (separates toy dinosaurs from toy cars). seems fascinated by, or engrossed in, figuring out situations: where the tennis ball rolled, where the dog went, what caused a particular noise. attends to self-selected activities for longer periods of time. discovering cause and effect: squeezing the cat makes them scratch. knows where familiar persons should be; notes their absence; finds a hidden object by looking in last hiding place first. (this is what piaget termed object permanence, which usually occurs during the sensorimotor stage of piaget's childhood theory of cognitive development) names familiar objects. recognizes, expresses, and locates pain. expected to use "magical thinking", the causal relationships between actions and events. tells about objects and events not immediately present (this is both a cognitive and linguistic advance). expresses more curiosity about the world. language enjoys participating while being read to. realizes language is effective for getting desired responses. uses 50 to 300 words; vocabulary continuously increasing. has broken the linguistic code; in other words, much of a two-year-old's talk has meaning to them. receptive language is more developed than expressive language; most two-year-olds understand significantly more than they can talk about. utters three- and four-word statements; uses conventional word order to form more complete sentences. refers to self as "me" or sometimes "i" rather than by name: "me go bye-bye"; has no trouble verbalizing "mine". expresses negative statements by tacking on a negative word such as "no" or "not": "not more milk." uses some plurals. some stammerings and other dysfluencies are common. 65 to 70 percent of speech is intelligible. is able to verbalize needs. asks a lot of questions. social and emotional shows signs of empathy and caring: comforts another child if hurt or frightened; appears to sometimes be overly affectionate in offering hugs and kisses to children continues to use physical aggression if frustrated or angry (for some children, this is more exaggerated than for others); physical aggression usually lessens as verbal skills improve. temper tantrums likely to peak during this year; extremely difficult to reason with during a tantrum. impatient; finds it difficult to wait or take turns. enjoys "helping" with household chores; imitates everyday activities: may try to toilet train a stuffed animal, feed a doll. "bossy" with parents and caregivers; orders them around, makes demands, expects immediate compliance from adults. watches and imitates the play of other children, but seldom interacts directly; plays near others, often choosing similar toys and activities (parallel play); solitary play is often simple and repetitive. offers toys to other children, but is usually possessive of playthings; still tends to hoard toys. making choices is difficult; wants it both ways. often defiant; shouting "no" becomes automatic. ritualistic; wants everything "just so"; routines carried out exactly as before; belongings placed "where they belong". three-year-old physical growth is steady though slower than in first two years. adult height can be predicted from measurements of height at three years of age; males are approximately 53% of their adult height and females, 57%. legs grow faster than arms. circumference of head and chest is equal; head size is in better proportion to the body. "baby fat" disappears as neck appears. posture is more erect; abdomen no longer protrudes. slightly knock-kneed. can jump from low step can stand up and walk around on tiptoes "baby" teeth stage over. needs to consume approximately 6,300 kj (1,500 kcal) daily. motor development walks up and down stairs unassisted, using alternating feet; may jump from bottom step, landing on both feet. can momentarily balance on one foot. can kick big ball-shaped objects. needs minimal assistance eating. jumps on the spot. can walk unassisted. bends over without falling. climbs objects well. starts to run easily, with knee flexion being used to support body weight. full control of feet in running movement pedals a small tricycle. throws a ball overhand; aim and distance are limited. catches a large bounced ball with both arms extended. enjoys swinging on a swing. shows improved control of crayons or markers; uses vertical, horizontal and circular strokes. holds crayon or marker between first two fingers and thumb (tripod grasp), not in a fist as earlier. can turn pages of a book one at a time enjoys building with blocks. builds a tower of eight or more blocks. enjoys playing with clay; pounds, rolls, and squeezes it. may begin to show hand dominance. carries a container of liquid, such as a cup of milk or bowl of water, without much spilling; pours liquid from pitcher into another container. manipulates large buttons and zippers on clothing. washes and dries hands; brushes own teeth, but not thoroughly. usually achieves complete bladder control during this time. cognitive development listens attentively to age-appropriate stories. makes relevant comments during stories, especially those that relate to home and family events. likes to look at books and may pretend to "read" to others or explain pictures. enjoys stories with riddles, guessing, and "suspense". speech is understandable most of the time. produces expanded noun phrases: "big, brown dog". produces verbs with "ing" endings; uses "-s" to indicate more than one; often puts "-s" on already pluralized forms: geeses, mices. indicates negatives by inserting "no" or "not" before a simple noun or verb phrase: "not baby." answers "what are you doing?", "what is this?", and "where?" questions dealing with familiar objects and events. four-year-old physical development head circumference is usually not measured after age three. requires approximately 7,100 kj (1,700 kcal) daily. hearing acuity can be assessed by child's correct usage of sounds and language, and also by the child's appropriate responses to questions and instructions. motor development walks a straight line (tape or chalk line on the floor). hops on one foot. pedals and steers a wheeled toy with confidence; turns corners, avoids obstacles and oncoming "traffic". climbs ladders, trees, playground equipment. jumps over objects 12 to 15 cm (5 to 6 in) high; lands with both feet together. runs, starts, stops, and moves around obstacles with ease. uses arm movement to increase running speed throws a ball overhand; distance and aim improving. builds a tower with ten or more blocks. forms shapes and objects out of clay: cookies, snakes and other simple animals. reproduces some shapes and letters. holds a crayon or marker using a tripod grasp. paints and draws with purpose; may have an idea in mind, but often has problems implementing it so calls the creation something else. becomes more accurate at hitting nails and pegs with hammer. threads small wooden beads on a string. can run in a circle can jump cognitive can recognize that certain words sound similar names eighteen to twenty uppercase letters. writes several letters and sometimes their name. a few children are beginning to read simple books, such as alphabet books with only a few words per page and many pictures. likes stories about how things grow and how things operate. delights in wordplay, creating silly language. understands the concepts of "tallest", "biggest", "same", and "more"; selects the picture that has the "most houses" or the "biggest dogs". rote counts to 20 or more. understands the sequence of daily events: "when we get up in the morning, we get dressed, have breakfast, brush our teeth, and go to school." when looking at pictures, can recognize and identify missing puzzle parts (of person, car, animal). very good storytellers. counts 1 to 7 objects out loud, but not always in order follows two to three step directions given individually or in a group may use the "-ed" ending improperly; for example: "i goed outside." language uses the prepositions "on", "in", and "under". uses possessives consistently: "hers", "theirs", "baby's". answers "whose?", "who?", "why?", and "how many?" produces elaborate sentence structures: "the cat ran under the house before i could see what color it was." speech is almost entirely intelligible. begins to use the past tense of verbs correctly: "mommy closed the door", "daddy went to work." refers to activities, events, objects, and people that are not present. changes tone of voice and sentence structure to adapt to listener's level of understanding: to baby brother, "milk gone?" to mother, "did the baby drink all of his milk?" states first and last name, gender, siblings' names, and sometimes own telephone number. answers appropriately when asked what to do if tired, cold, or hungry. recites and sings simple songs and rhymes. social development outgoing; friendly; overly enthusiastic at times. moods change rapidly and unpredictably; laughing one minute, crying the next; may throw tantrum over minor frustrations (a block structure that will not balance); sulk over being left out. imaginary playmates or companions are common; holds conversations and shares strong emotions with this invisible friend. boasts, exaggerates, and "bends" the truth with made-up stories or claims of boldness; tests the limits with "bathroom" talk. cooperates with others; participates in group activities. shows pride in accomplishments; seeks frequent adult approval. often appears selfish; not always able to take turns or to understand taking turns under some conditions; tattles on other children. insists on trying to do things independently, but may get so frustrated as to verge on tantrums when problems arise: paint that drips, paper airplane that will not fold right. enjoys role-playing and make-believe activities. relies (most of the time) on verbal rather than physical aggression; may yell angrily rather than hit to make a point; threatens: "you can't come to my birthday party." name-calling and taunting are often used as ways of excluding other children. can be bossy at times, telling their parents to stop talking, or telling their friends to "come here right now." establishes close relationships with playmates; beginning to have "best" friends. begins to ask questions about own and others' bodies may attempt to see others naked in the bathroom middle childhood five-year-old physical head size is approximately that of an adult's. may begin to lose "baby" (deciduous) teeth. body is adult-like in proportion. requires approximately 7,500 kj (1,800 kcal) daily visual tracking and binocular vision are well developed. motor development walks backwards, toe to heel. walks unassisted up and down stairs, alternating feet. may learn to turn somersaults (should be taught the right way in order to avoid injury). can touch toes without flexing knees. walks a balance beam. learns to skip using alternative feet. catches a ball thrown from 1 m (3.3 ft) away. rides a tricycle or wheeled toy with speed and skillful steering; some children learning to ride bicycles, usually with training wheels. jumps or hops forward ten times in a row without falling. balances on either foot with good control for ten seconds. builds three-dimensional structures with small cubes by copying from a picture or model. reproduces many shapes and letters: square, triangle, a, i, o, u, c, h, l, t. demonstrates fair control of pencil or marker; may begin to color within the lines. cuts on the line with scissors (not perfectly). hand dominance is fairly well established cognitive forms rectangle from two triangular cuts. builds steps with set of small blocks. understands concept of same shape, same size. sorts objects on the basis of two dimensions, such as color and form. sorts a variety of objects so that all things in the group have a single common feature (classification skill: all are food items or boats or animals). understands the concepts of smallest and shortest; places objects in order from shortest to tallest, smallest to largest. identifies objects with specified serial position: first, second, last. rote counts to 20 and above; many children count to 100. recognizes numerals from 1 to 10. understands the concepts of less than: "which bowl has less water?" understands the terms dark, light, and early: "i got up early, before anyone else. it was still dark." relates clock time to daily schedule: "time to turn on the tv when the little hand points to 5." some children can tell time on the hour: five o'clock, two o'clock. knows what a calendar is for. recognizes and identifies coins; beginning to count and save money. many children know the alphabet and names of upper- and lowercase letters. understands the concept of half; can say