Even the healthiest newborn may have an unearthly look about him: a wizened little red face, pointy head, spindly limbs that may tremble and shake, skin that is bumpy or peeling. Although helpless now except for sucking and grasping reflexes, he will grow very quickly.

By the fourth week's end, he can probably:

• Focus on your face, crib toys and mobiles
• Calm down when you speak to him gently and hold him upright against your shoulder
• Startle, cry or quiet down in response to loud or sudden noises
• Turn toward your voice
• Make an "ah" sound when he sees your face and hears you speak

Encourage your baby by:

Showing him that the world is a warm place. Cuddle, soothe and respond quickly to his needs. He doesn't need a crib full of bright toys yet. Your face and voice are his most fascinating playthings.

Month Two

Your baby is settling into recognizable eating and sleeping patterns. Prepare to be captivated by her first real social smile when she is about six or seven weeks old.

By the eighth week's end, she can probably:

• Smile in response to your smile
• Begin to track an object with her eyes
• Make a variety of gurgles, grunts and humming sounds to express her feelings
• Lift her head 45 degrees when lying on her stomach
• Recognize breast or bottle and squirm eagerly for it when she is hungry
• Bat at a toy with her closed fist
• Keep her head up when held in a sitting position with occasional bobs forward

Encourage your baby by:

Acknowledging her new, sociable moods. Smile and talk to her frequently. When you pause, she will "answer" you by smiling and cooing. Show her musical toys, and help her play with and track a rattle. Watch her signals. If she starts turning away or closing her eyes, it usually means that she has had enough stimulation.

Month Three

Increasingly aware of his surroundings, your baby scrutinizes toys and objects, his hands and feet. He is beginning to have more control over his limbs - much to his delight - and may spend a great deal of time kicking his legs and batting at objects. Encourage his physical freedom by letting him play on a soft rug that is protected by a clear towel or blanket. Note: If your baby has been colicky, crying spells should begin to diminish or even cease near the end of month three.

By the end of the month, he can probably:

• Lift his head up 90 degrees when he is on his stomach
• Bring both hands together
• Laugh and chuckle
• Smile at you from across the room (his distance vision is improving)
• Roll from stomach to back
• Enjoy playing, and he may even cry when interrupted

Encourage your baby by:

Giving him just a few playthings at any one time so that he won't be overwhelmed. Make sure that all objects near him are clean, safe, nontoxic, and too big to fit comfortably into his mouth.

Month Four

Your baby is growing ever more enchanting. By the end of this month, she begins sleeping a decent stretch at night and has a predictable morning and afternoon nap time. When she is up, she is likely to be bubbling with pleasure and good spirits. She is starting to realize that she influences the world around her, and will try to figure out how one action affects another. Don't be surprised to find her banging a rattle or dropping a toy over and over again just to see what happens.

By the end of the month, she can probably:

• Roll from stomach to back and back to stomach. She may even use rolling to get closer to things
• Put everything within reaching distance into her mouth - a sign of exploration, not teething
• Increase her sound repertoire by blowing raspberries, shrieking, chuckling
• Hold her head steady when held in a sitting position
• Grasp and shake a rattle
• Reach for an object, although she often overshoots the mark
• Be fascinated for minutes exploring her own hands

Encourage your baby by:

Introducing games such as "this little piggy" and pat-a-cake. Help her language skills along by imitating her sounds. She will love it and answer back. She will also enjoy such exercises as being gently pulled into a sitting position. Note: Do not turn your back on her even for an instant while she is on a bed or a changing table. At this age, she is very likely to roll off!

Month Five

Your five-month-old is reaching accurately, using his hands to explore the world, and rolling with ease. His physical activity helps strengthen his muscles in preparation for sitting and crawling, although for some babies this goal is still far away.

By the end of the month, he can probably:

• Briefly sit in a tripod formation
• Lift both arms and legs in a Superman pose, while he is on his stomach
• Do modified push-ups and make swimming motions with his arms and legs
• Delight in his own reflection
• Enjoy rhythm and music
• Become increasingly adept at bringing objects to his mouth for oral exploration

Encourage your baby by:

Continuing with gentle sit-ups. Vary sit-ups by pulling baby up into a standing position. To help him stay balanced while he sits, place a favorite toy or book in from of him. Read him a book with bright illustrations. He'll particularly enjoy simple poems or rhymes.

Month Six

Big doings are ahead this month. Your baby is sitting up without help and may even have cut her first tooth. She is increasingly able to express her feelings, especially her positive ones about you. Her whole body radiates joy when she sees you! She may raise her arms to be picked up, snuggle against you, and reserve her best smile for you alone.

By the end of the month, she can probably:

• Sit independently
• Make consonant-vowel sounds such as "ba," "ma," "pa," and "do," and put them together in long, melodious strings of gibberish
• Hold her own bottle
• Show a certain amount of wariness in front of strangers, and may cry when you leave the room
• Begin to pass objects from hand to hand

Encourage your baby by:

Playing peekaboo to reinforce the idea that you can go away and come back. Take her out often, and introduce her to other children (but don't expect her to play with them). Help her strengthen her legs by occasionally holding her in a standing position when playing. Note: Electric cords and outlets pose serious hazards. Provide a safe environment for your little explorer by baby-proofing your house, if you haven't already done so.

Month Seven

By the end of this month, your baby is really honing his skills. He is standing with support, vocalizing and improving his hand-eye coordination. He'll probably be teething too. Expect the bottom two front teeth to poke through at six and a half to seven months, followed by the top two teeth four to eight weeks later.

If he has shown previous signs of stranger anxiety, he may be even more wary now. Your baby may also be increasingly clingy and upset when you leave the room. This type of behavior is a sign of separation anxiety and is a normal developmental stage.

By the end of the month, he can probably:

• Stand with support
• Sit comfortably and steadily
• Go from a sitting to a crawling position
• Communicate some of his basic needs

Encourage your baby by:

Not keeping him cooped up in a playpen; he needs plenty of room to roam. Offer him soft, rubbery toys to chew on to help ease teething discomfort.

Month Eight

Your baby is increasingly independent but may also be very clingy when a stranger is around. Her sleep patterns may be disturbed by her fear of being alone. She will call out to you for reassurance. In spite of her stranger anxiety, she will probably enjoy spending time with another baby.

By the end of the month, she can probably:

• Feed herself a cracker or small pieces of food
• Look for a dropped object
• Take sips from a cup (but expect spills)
• Crawl or creep - but not necessarily in the direction that she wants to go
• Pull up into a standing position
• Use her index finger to poke at things

Encourage your baby by:

Clearing breakables off low tables and keeping closets and cabinets locked to give her free movement around your home. You might consider giving her own kitchen cabinet and filling it with plastic and lightweight metal pots, pans and utensils. If she doesn't know how to get down from a standing position, help her bend her knees so that she can lower herself to the floor without falling. A routine (bath, song, and a firm but loving "night-night") will make bedtime easier. A familiar blanket or cuddly toy can also be a big source of help and comfort; safeguard this important object! Month Nine

Your nine-month-old is making both physical and intellectual strides. He is playing in an entirely new way: using two toys at the same time, beginning to stack and sort objects, and putting small toys in a pail or pot. He can also understand more words and gestures, so keep him busy in conversation. He may oblige your request of him to wave bye-bye or play "so big." Note: Look for the appearance of his top and bottom lateral incisor teeth. They should break through during the ninth or tenth month.

By the end of the month, he can probably:

• Crawl up stairs
• Say "mama" or "dada"
• Creep, crawl or take a few steps with some support from you
• Enjoy water play
• Feed himself finger food, and he may have taste preferences
• Respond to his name

Encourage your baby by:

Letting him hold onto your fingers while he practices his toddling skills. It's time to introduce more sophisticated toys with multiple parts, such as shape sorters and stacking ups. Continue to play, talk and read to him.

Month Ten

Your active ten-month-old may resent being confined to a stroller or car seat. She would rather be out and about on her own and will communicate her preference loudly. Since it's not always safe or convenient to let her have her way, keep confining trips to a minimum, if possible, and offer her lots of opportunities to get around by herself.

Stranger and separation anxieties are increasing, and she may show a sudden fearfulness of routines or sounds that did not bother her before, such as: having a shirt pulled over her head, or hearing the vacuum, a siren or a whistling teapot.

By the end of the month, she can probably:

• Stand with little support
• Sit down from a standing position
• Roll a ball
• Pretend to talk on a toy telephone
• Play peekaboo herself
• Search for an object if she has seen it hidden
• Repeat sounds and gestures for attention
• Pick up very small objects between thumb and forefinger

Encourage your baby by:

Being tactful and gentle when dealing with fears. Give reassuring hugs, and don't force her to touch or handle a feared object. In time, her fears will dissipate.

Month Eleven

Sometime during the eleventh month, your baby will probably start walking, holding on to the furniture for support. Cruising, as it is called, is soon followed by a baby's first independent step. Let your baby cruise barefoot indoors for the best possible traction.

By the end of the month, he can probably:

• Make long babbling sentences
• Say one word other than "mama" or "dada"
• Hold out his arm or leg to help you dress him
• Drop objects for someone to pick up
• Drink independently from a cup
• Understand simple commands such as "Bring me the book" or "Hug the teddy"

Encourage your baby by:

Showing your appreciation when he helps out at dressing time. Take falls in stride by saying "uh-oh" instead of "oh no." Now is a good time to introduce a stable riding toy.

Month Twelve

Your twelve-month-old may seem like a perpetual-motion machine, but her attention span for quiet activities is also increasing. Now might be a good time to introduce longer picture books. She may also concentrate for as long as fifteen minutes on an activity such as emptying out and playing with the contents of a laundry basket. Your baby's first set of molars are beginning to erupt.

By the end of the month, she can probably:

• Give a kiss on request
• Give and take a toy
• Walk with or without help
• Point to objects that she wants
• Imitate activities of adults and older siblings, such as brushing hair, stirring a bowl, blowing on hot food
• Play to a crowd and repeat an action if her audience laughs
• Enjoy pull-and-push toys
• Scribble with a chunky crayon if you tape paper to a work surface

Encourage your baby by:

Applauding her determined efforts to walk independently to your outstretched arms. Mastering this and other physical skills is your baby's top priority right now. Before you know it, she'll be off and running straight into toddlerhood.