12 to 24 Months: Development, Research, and What Helps

CDC's milestone checklists list skills that at least 75% of children show by each age, so a missed milestone is a reason to check in, not to wait and see (Zubler et al., 2022). Born early? Use your child's corrected age for milestones during the first 2 years (AAP).

Milestones by 12 and 15 months

By 12 months, most babies (CDC):

• Social: play games with you, like pat-a-cake.
• Communication: wave bye-bye, call a parent "mama," "dada," or another special name, and understand "no" (they pause or stop when you say it).
• Thinking: put something in a container, like a block in a cup, and look for things they see you hide.
• Movement: pull up to stand, walk holding on to furniture, drink from an open cup you hold, and pick up small things between thumb and pointer finger.

By 15 months, most toddlers (CDC):

• Social: copy other children during play, show you an object they like, clap when excited, hug a stuffed toy, and show you affection.
• Communication: try to say one or two words besides "mama" or "dada," look at a familiar object when you name it, follow directions given with both a gesture and words, and point to ask for something or get help.
• Thinking: try to use things the right way, like a phone, cup, or book, and stack at least two small objects.
• Movement: take a few steps on their own and feed themselves some food with their fingers.

Milestones by 18 months and 2 years

By 18 months, most toddlers (CDC):

• Social: move away from you but check that you're close by, point to show you something interesting, hold out their hands to be washed, look at a few pages of a book with you, and help you dress them.
• Communication: try to say three or more words besides "mama" or "dada," and follow one-step directions without a gesture.
• Thinking: copy chores, like sweeping, and play with toys in simple ways, like pushing a toy car.
• Movement: walk without holding on, scribble, drink from an open cup with some spills, feed themselves with their fingers, try a spoon, and climb on and off a couch or chair.

By 2 years, most toddlers (CDC):

• Social: notice when others are hurt or upset, and look at your face to see how to react in a new situation.
• Communication: point to things in a book when you ask, put at least two words together, like "More milk," point to at least two body parts, and use gestures like nodding yes.
• Thinking: hold something in one hand while using the other, try switches, knobs, or buttons on toys, and play with more than one toy at a time.
• Movement: kick a ball, run, walk up a few stairs with or without help, and eat with a spoon.

When the checklists were rewritten in 2022, two-thirds of the milestones that changed ages moved later (Zubler et al., 2022). Speech-language pathologists worried this could slow referrals; CDC said the checklists are for tracking, not for deciding who qualifies for help (ASHA).

From first steps to running

First steps have one of the widest normal windows of any motor milestone. In a WHO study of 816 children in Ghana, India, Norway, Oman, and the US, nearly all healthy children started walking alone between 8.2 and 17.6 months (WHO Multicentre Growth Reference Study Group, 2006). By 2, most toddlers run and kick a ball (CDC).

Hands get busy too: towers of up to four blocks, turning pages, and scribbling, then five or six blocks nearing age 2. Many children don't show a dominant hand for years, and there's no need to push one (AAP).

Words, gestures, and two-word phrases

Early in the second year, toddlers suddenly seem to understand much of what you say (AAP). Between 18 months and 2 years, many learn about one new word a week. By 2, most say about 50 to 100 words, use several two-word phrases like "Daddy go" or "All gone," and are understood by others about half the time (AAP).

Pointing is a big deal. Toddlers point to get you to look, point so you'll name things, and bring objects to show you (AAP). Learning two languages doesn't cause delays. Count words across both: 25 words in English plus 25 in Spanish equals 50 (AAP).

Thinking and pretend play

Your toddler is running experiments: dropping, dumping, filling, and finding. By 12 months they look for a toy they saw you hide; by 18 months they push a toy car or copy you sweeping (CDC; CDC). Simple pretend play, like feeding a stuffed animal with a spoon, is worth trying now (CDC). Stacking and fitting things together teach ideas like "in," "on," and "under" (AAP).

Big feelings, clinginess, and "mine"

Expect your toddler to swing between fierce independence and clinging to you, especially when tired, sick, or scared. This is normal (AAP). Many toddlers who breezed through goodbyes as babies start protesting at 15 or 18 months (AAP).

Toddlers play alongside other children more than with them. Sharing means little yet, and grabbing and hitting are common. By about 18 months, many say their own name and recognize themselves in a mirror (AAP). The all-purpose "No!" is a sign of a growing sense of self, not defiance (AAP). Tantrums happen most between ages 1 and 3 (Swanson, AAP).

Sleep and the move to one nap

Children ages 1 to 2 need 11 to 14 hours of sleep a day, naps included, with regular sleep and wake times (WHO). In a study that followed 172 children, two naps a day were well established by 9 to 12 months, and one afternoon nap by 15 to 24 months (Weissbluth, 1995). Dropping naps entirely is rare this early: in a 2020 review, fewer than 2.5% of children stopped napping before age 2 (Staton et al., 2020).

Growth, appetite, and teeth

Growth slows down. Most toddlers gain only 3 to 5 pounds during the whole second year, and by 2 their head is about 90% of its adult size (AAP). So appetite drops, often sharply, after the first birthday. One-year-olds need about 1,000 calories a day across three meals and two snacks, and their eating is erratic from day to day (AAP).

Brush twice a day with a smear of fluoride toothpaste the size of a grain of rice, and see a dentist by the first birthday or within 6 months of the first tooth (AAP).

Some of this year's best-known findings are solid. A few famous ones are still being argued about.

1. Walking is learned one fall at a time. In a 2012 study of free play, 12- to 19-month-olds averaged 2,368 steps and 17 falls per hour. New walkers improved fast, taking more steps and falling less (Adolph et al., 2012). Takeaway: Give your toddler safe room to roam and lots of time. Tumbles are part of the practice.

2. Toddlers want to help, and rewards can dampen it. In lab studies, 18-month-olds helped an unfamiliar adult without being asked, for example by picking up a marker he dropped by accident or opening a cabinet he couldn't open (Warneken & Tomasello, 2006). When he dropped a clothespin, they usually helped within 10 seconds, with no thanks or reward (Max Planck Society, 2006). Even 14-month-olds handed over objects an adult was reaching for (Warneken & Tomasello, 2007). Among 36 toddlers about 20 months old, those given a toy for helping later helped less than those who got praise or nothing (Warneken & Tomasello, 2008). At home, most children start helping around their first birthday (Dahl, 2015). Takeaway: Your toddler's urge to help is real. Welcome it and say thank you; skip the treats.

3. The "30-million-word gap" is contested. Hart and Risley's 1995 claim that poor children hear 30 million fewer words than middle-class children wasn't supported when researchers recorded 42 children in five US communities and counted talk from everyone around them (Sperry et al., 2019). Others argue that speech aimed directly at a child is what counts, and that gap is real (Golinkoff et al., 2019). A 2022 meta-analysis of 19 studies found lower-income children heard less child-directed speech, but far less than a 30-million-word gap (Dailey & Bergelson, 2022). Conversation may matter most. In 146 children, back-and-forth turns at 18 to 24 months predicted IQ and vocabulary 10 years later, even accounting for family socioeconomic status; plain word counts held up less well (Gilkerson et al., 2018). That's a correlation, not proof. Takeaway: Aim for turns, not word counts. Any family can do this.

4. Spanking doesn't work, and it's linked to worse behavior. The AAP says physical punishment, yelling, and shaming work poorly in the short term and not at all in the long term (Sege & Siegel, 2018). Meta-analyses covering 160,927 children linked spanking to more behavior problems and other poor outcomes (Gershoff & Grogan-Kaylor, 2016). A review of 69 long-term studies found physical punishment predicted more behavior problems over time and wasn't linked to any positive outcomes (Heilmann et al., 2021). Most of this research is observational, and one meta-analysis found the effects small once earlier behavior was accounted for (Ferguson, 2013). Takeaway: The debate is over how much harm spanking does, not whether it helps. Use calmer tools.

5. Autism screening finds many children early, though not all. The AAP recommends autism screening at 18 and 24 months (Hyman et al., 2020). In 16,071 toddlers screened with the M-CHAT-R/F questionnaire, 47.5% of children who screened positive after a follow-up interview had autism, and 94.6% had some developmental delay or concern (Robins et al., 2014). Across 50 studies, it caught 83% of children with autism (Wieckowski et al., 2023). In 2016, the US Preventive Services Task Force found too little evidence to judge screening children with no concerns (Siu et al., 2016). Studies of early autism support show some benefits, but many have quality problems (Sandbank et al., 2023). Takeaway: Fill out the questionnaire. A positive screen isn't a diagnosis, and a negative one doesn't override your concerns.

6. Toddlers learn less from screens than from people. Across 59 reports, children up to age 6 learned less from video than from a person, by about half a standard deviation. The gap shrank with age, and the authors flagged possible publication bias (Strouse & Samson, 2021). Live video chat may be different: 12- to 25-month-olds learned more from a FaceTime partner than from a recorded video (Myers et al., 2017). In 2,441 Canadian children, more screen time at 24 and 36 months predicted slightly lower developmental screening scores a year or two later (Madigan et al., 2019). Takeaway: People first. If you use screens, keep them short, good, and shared.

7. Picky eating is common and often yields to repetition. In a national sample of 3,022 children, caregivers called 19% of 4-month-olds picky eaters, rising to 50% by 24 months. Caregivers offered a new food at most three to five times before deciding their child disliked it (Carruth et al., 2004). A review of 21 studies found moderate evidence that offering a taste of a vegetable or fruit daily for 8 to 10 days or more helps children up to 24 months accept it (Spill et al., 2019). Takeaway: "No" today isn't "no" forever. Keep offering without pressure.

Childproof first, say "no" less

Your toddler can open drawers and climb onto counters but can't understand danger or remember "no" while exploring (AAP). So change the space, not just the child. Move hazards out of reach, redirect quickly, and save "no" for danger (CDC). The AAP suggests positive directions over "don't": "Feet on the floor," not "Don't climb" (AAP).

Script: "That's Daddy's phone. Here's your phone." (Hand over a toy and walk away from the real one.)

Riding out tantrums

• Before: Hunger and tiredness set off many tantrums, so protect naps and carry snacks (Swanson, AAP). Offer simple choices between two things you're happy with (CDC).
• During: Stay calm and close. Try distraction, or give your toddler time to calm down in a safe, quiet spot near you (CDC). Hitting, biting, or running into danger need you to step in right away (Swanson, AAP).
• After: Reconnect and name the feeling you saw (CDC). Consistency from day to day is key to fewer tantrums, and giving in a little now and then is okay (Swanson, AAP).

Tantrums are close to universal: in a study of 1,490 children ages 3 to 5, 83.7% had tantrums sometimes, but only 8.6% had them daily. The tantrums that stood out as possible problems were unpredictable, very long, or destructive, so raise those with your pediatrician (Wakschlag et al., 2012).

Script: "You're so mad. You wanted the red cup. I'm right here." (Then wait.)

Discipline that teaches

The AAP's approach rests on attention: notice and praise what you want to see, calmly ignore minor misbehavior that isn't dangerous, and redirect a bored toddler to something else (AAP). For toddlers, the AAP says to try short time-outs if needed (AAP), with a rule of thumb of 1 minute per year of age (AAP). With a 1-year-old, that often just means calmly moving them away from the problem. In one long-term study, parents' use of time-out at age 3 wasn't linked to later emotional or behavior problems (Knight et al., 2020).

Hitting and biting. Toddlers lack the self-control to show anger peacefully. Separate children, say calmly that hurting isn't allowed, show what to do instead, and praise gentle touches. Call your pediatrician if your child seems unusually aggressive for more than a few weeks (AAP).

Script: "Ouch. Biting hurts. I won't let you bite. You can stomp your feet when you're mad."

When you lose it. Put your toddler somewhere safe and take a few minutes yourself. Then go back, hug, and start over; if you yelled, apologize (AAP).

Talk with your toddler, not just to them

When your toddler points, babbles, or says a word, answer, then pause for their turn. These back-and-forth exchanges help build the brain's connections (Harvard Center on the Developing Child).

• Expand. Your toddler says "Dog." You say "Dogs say woof, woof" (CDC).
• Model, don't correct. Repeat words back correctly ("That's right, it's a ball!") instead of pointing out mistakes (AAP).
• Use real names, including for body parts: toes, not "piggies" (AAP).
• Go one-on-one. In home recordings of 26 babies, one-on-one "parentese" (the slow, warm, sing-song voice) at 11 and 14 months was linked to more words at 24 months (Ramírez-Esparza et al., 2014). Use whichever languages you're most comfortable in (AAP).

Mealtimes without battles

Your job is to offer a range of healthy foods; your toddler decides how much to eat (CDC). Encourage, but don't pressure; intake tends to balance out over several days (AAP). Keep putting a refused food on the plate; the new US Dietary Guidelines note it may take 8 to 10 exposures before a young child will try it (USDA & HHS, 2026).

• Milk: At 12 months, plain whole milk can start: 2 to 3 cups (16 to 24 ounces) a day until age 2. Toddler milks aren't recommended, and plant milks other than soy shouldn't replace dairy unless there's a medical or dietary reason (AAP). More than 24 ounces a day can crowd out iron-rich foods (AAP).
• Other drinks: Water between meals. If you serve juice, keep it to 4 ounces or less of 100% juice a day (CDC), and avoid added sugars in early childhood (USDA & HHS, 2026).
• Fats and iron: Don't cut fat; toddlers need it to grow (AAP). Offer iron-rich foods like beef, eggs, lentils, tofu, and iron-fortified cereal (AAP).
• Choking: Seated, supervised eating, with food cut into pieces no bigger than half an inch (AAP). Quarter hot dogs lengthwise before slicing, and spread nut butters thinly (AAP).

From bottle to cup

The AAP suggests finishing the move from bottle to cup between 12 and 18 months. Longer bottle use is linked to skipped meals, extra weight, and cavities. Drop the nap and bedtime bottles first, offer a cup at meals, and aim for an open cup by about 2 (Shu, AAP). Breastfeeding can continue as long as you and your child want, to age 2 or beyond (USDA & HHS, 2026).

Naps, bedtime, and night waking

• Keep a short, steady bedtime routine. In a 3-week trial of 405 families with children 7 to 36 months old, a consistent nightly routine helped children fall asleep faster and wake less, and mothers' moods improved (Mindell et al., 2009). The AAP suggests "brush, book, bed" (AAP).
• Plan the crib exit. Most crib falls happen during climbing out, so move your toddler to another bed at 35 inches tall (AAP) or once they can climb out. Keep the same routine, gate the doorway and stairs, and praise your toddler in the morning for staying in bed (Moon, AAP).

Screens in the second year

The advice has shifted. In 2026, the AAP replaced its earlier media guidance (AAP, 2026) with a policy that moves away from fixed time rules. It says infants don't learn from digital media, but an occasional brief, high-quality video isn't harmful, and families who want a limit might aim for under an hour a day for toddlers (Munzer et al., 2026). WHO is stricter: no sedentary screen time for 1-year-olds, and no more than an hour at age 2 (WHO). Either way:

• Video calls with family are fine (CDC).
• Watch together and talk about what you see, and put your own phone down at meals and bedtime (Munzer, AAP).
• Turn the TV off when no one is watching, and keep meals and bedtime screen-free (Munzer et al., 2026).

Easier goodbyes

For drop-offs, the AAP suggests a quick, loving goodbye ritual, done the same way each time. Give full attention, then leave, even through tears. Describe your return in toddler terms ("after nap, before snack"), and keep your promise (Swanson, AAP). Don't sneak out; toddlers who never know when you'll vanish may cling more (AAP).

Your toddler learns mostly through routines and copying you. This year's curriculum:

• Words for everything, including feelings. Name what you think your toddler feels (CDC), and talk about how others feel (CDC).
• Gentle hands. Toddlers need rules taught, not assumed (AAP).
• What comes next. Steady routines for meals, naps, and bedtime (CDC).
• Small choices. "Red cup or blue cup?" (CDC)
• Self-care steps. Holding out hands to wash and pushing an arm through a sleeve (CDC). Nearing 2, many can wash hands and brush teeth if shown how (AAP).

Family jobs for helpers in diapers

Toddlers copy household chores and love to join in (see the research above). CDC suggests including your child in everyday tasks, like fetching shoes, putting snacks in a bag, or carrying napkins to the table (CDC; CDC). The AAP's advice: even if it takes longer, make it a game, and if a job is unsafe, find another one they can do. Don't discourage the urge to help (AAP).

Tiny jobs that fit this age:

• Toys into a bin, with a clean-up song
• Socks into the laundry basket, or pulling clean clothes out of the dryer
• Napkins or spoons to the table
• Fetching their own shoes, diaper, or jacket
• Wiping a spill with a cloth
• Putting snacks into a bag

How to make it work:

• Show, then do it together. Your toddler copies what you do.
• Expect "unhelpful help." In a survey of more than 500 families, most parents of 1- to 4-year-olds said their child's help was sometimes unhelpful (Hammond & Brownell, 2018). That's normal.
• Thank them and describe the effort. "You carried all the napkins!" In a small study of 53 families, parents' praise of effort at 14 to 38 months predicted children's belief at 7 and 8 that ability can grow (Gunderson et al., 2013). Keep expectations modest, though: across studies, mindset's link to school achievement is weak (Sisk et al., 2018).
• Keep it unpaid. These are family jobs, part of belonging. Toy rewards made 20-month-olds less likely to keep helping (Warneken & Tomasello, 2008). Families differ: in one study, Mexican-heritage students recalled pocket money as a gift not tied to chores, while European American students recalled allowances paid for chores (Coppens & Alcalá, 2015). Optional paid extras and money lessons come later; see the age 3 guide, how to reward without bribery, and chores that build independent kids.

Safety note: Keep helping away from the stove, hot drinks, cleaning products, and buckets of water (AAP).

These are for a toddler on the move with an adult close by. Keep them short, follow your toddler's lead, and stop when interest fades. Repeating favorites is fine.

Injuries are the biggest threat

The AAP calls injuries the biggest threat to a toddler's life and health, and most can be prevented. Your toddler can walk, climb, and open things, but can't yet understand danger (AAP). Barriers and supervision do the work that "no" can't.

Water

More children ages 1 to 4 die from drowning than from any other cause (CDC). In one analysis, 69% of drownings in children 4 and under happened when they weren't expected to be in the water (AAP).

• Stay within arm's reach in the bath and near any water. Never leave your toddler with another child in charge (AAP, 2026).
• Fence pools, including big inflatable ones, on all 4 sides with a fence at least 4 feet high and a self-closing, self-latching gate (AAP).
• Empty buckets, wading pools, and coolers right after use, and keep bathroom doors closed (AAP).
• Swim lessons can start after the first birthday (AAP, 2026). In one case-control study, formal lessons were linked to an 88% lower drowning risk at ages 1 to 4, with wide uncertainty (Brenner et al., 2009). Lessons don't make a toddler water-safe (AAP).
• Learn CPR (AAP, 2026).

Car seats

Rear-facing until your toddler reaches the seat's rear-facing limit, every ride, with the harness snug, the chest clip at armpit level, and no bulky coat under the straps (AAP). The back seat is safest. Never leave your toddler alone in a car, and walk behind the car before backing out (AAP).

Medicines, cleaners, and batteries

• Keep medicines and household products out of sight and reach, in their original containers, with safety caps on (AAP).
• If your toddler swallows something poisonous, call Poison Help at 1-800-222-1222 right away, and don't make them vomit (AAP).
• Use traditional detergent instead of laundry packets while young children live in or visit your home (AAP).
• A coin battery from a remote, key fob, or toy can burn through the food pipe within 2 hours. Tape battery compartments shut. If your toddler might have swallowed one, call 911 or go to the ER. While you wait for care, a child over 12 months who can swallow can have 2 teaspoons of honey every 10 minutes, up to 6 doses, but don't delay care to find it (AAP).

Burns and scalds

Keep your toddler out of the kitchen while you cook, keep hot drinks out of reach, and never hold your toddler and a hot drink at the same time. Set your water heater so the hottest water at the tap is no more than 120°F. Put working smoke alarms on every level of your home. For a burn, put cold water on it for a few minutes, cover it loosely, and call your pediatrician (AAP).

Falls, windows, and tip-overs

• Stairs and windows: Use gates on stairs and window guards above the first floor (AAP). Window stops should keep windows from opening more than 4 inches, and screens won't stop a fall. About 5,600 children 12 and under were treated in emergency departments for window falls in 2024 (CPSC, 2026).
• Furniture and TVs: Anchor dressers, bookcases, and TVs to the wall. A child is treated in an emergency department for a tip-over injury about every 53 minutes, and more than half of reported tip-over deaths from 2013 to 2023 were children ages 1 to 3 (CPSC, 2024).
• Climbing: Move chairs away from counters and windows (AAP).

Choking

Balloons, balls, marbles, toy parts, and coins are common choking hazards. Hold off on nuts, popcorn, hard or sticky candy, gum, raw carrots, and chunks of meat or cheese until age 4 or later. Round, firm foods like hot dogs and grapes are okay only if chopped into tiny pieces (AAP). Balloons stay a hazard until age 8. A CPR and first aid class is worth taking (AAP).

Guns in the home

The safest home for a child has no guns. If you keep one, store it unloaded and locked, with ammunition locked separately, and ask about guns and storage in homes your toddler visits (AAP). In a case-control study, guns involved in youth suicide attempts and unintentional shootings were much less likely to have been stored locked or unloaded (Grossman et al., 2005).

Call 911 if your toddler

• Is struggling for each breath, can barely cry, has bluish lips, or has stopped breathing (AAP)
• Choked on something that could be stuck in their throat (AAP)
• Can't be woken up, or is not moving or too weak to stand (AAP)
• Has purple or blood-colored spots on the skin with a fever (AAP)
• After a head injury, has a seizure, was knocked out for more than a minute, or is confused or unsteady (AAP)

Go to the ER now if your toddler

• Might have swallowed a button battery or a magnet, or can't swallow, drools, or gags after swallowing something (AAP)
• Has ribs pulling in with each breath, or loud wheezing or harsh noisy breathing (AAP)
• Had a seizure with a fever, has a stiff neck, or is hard to wake or "out of it" (AAP)
• Vomited 2 or more times after a head injury, or cries nonstop after one (AAP)

Call your pediatrician right away if your toddler

• Has a fever over 104°F (40°C), or seems dehydrated: no urine in more than 8 hours, a very dry mouth, and no tears (AAP)
• Won't move an arm or leg normally, or cries when touched or moved (AAP)
• Has any burn (AAP), or had a serious fall or isn't acting normally after one (AAP)
• Looks or acts very sick, or you think they need to be seen urgently (AAP)

Call within a day for a fever that lasts more than 3 days, or more than 48 hours with no other symptoms in a child under 2 (AAP).

Don't wait on development worries

If your toddler isn't meeting milestones, has lost skills, or you're simply worried, talk with your pediatrician and ask about developmental screening (CDC). You can also call your state's early intervention program for a free evaluation. You don't need a referral or a diagnosis (CDC). Bring it up if your toddler:

• Isn't walking on their own by 18 months (CDC)
• Doesn't point to show you things, wave, or respond when you play simple games (CDC)
• Isn't trying to say three or more words by 18 months, or isn't putting two words together by 2 (CDC; CDC)
• Doesn't seem to hear you, or doesn't notice when you come into the room (AAP)
• Has tantrums that are very long, destructive, or come out of nowhere (Wakschlag et al., 2012)
• Has lost words or skills they used to have

The 12-, 15-, 18-, and 24-month checkups

The AAP recommends well visits at 12, 15, 18, and 24 months (AAP, 2025). Expect:

• 12 months: vaccines, an anemia check, and lead screening based on risk or local rules (AAP, 2025). Iron screening timing also depends on diet (AAP).
• 15 months: any vaccine doses that are due, plus fluoride varnish, which the AAP recommends every 6 months (every 3 if cavity risk is high) (AAP).
• 18 months: a developmental screen and an autism screen, both questionnaires you fill out (AAP).
• 24 months: a second autism screen and lead screening based on risk or local rules (AAP, 2025).

For vaccines, see What vaccines does my toddler get between 12 and 24 months? above. Bring your questions in writing.

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