Ages 2–3

✅Key checklist for this stage

• In Korea, keep track of the 5th (30–36 months) and 6th (42–48 months) infant health checkups and the 2nd dental checkup (42–53 months).
• Get a flu shot every autumn and check remaining vaccines such as Japanese encephalitis in the immunization registry.
• When readiness signs appear, start potty training without rushing.
• Keep screens under 1 hour a day, ideally watching together and talking about it.
• Have your child's vision tested around ages 3–4 to check for amblyopia (lazy eye).

🧠Development — words and imagination

Gross motor: running, jumping with both feet and pedaling a tricycle come one after another. Around age 3, many climb stairs alternating feet.

Fine motor: copies a circle, builds tall towers, and gets better at buttons and twisting lids.

Language: two-word phrases at age 2 grow into sentences of three or more words by about age 3. Strangers can usually understand most of what the child says, and 'Why?' and 'What's that?' questions multiply. Unclear pronunciation is common at this age.

Social and emotional: children enjoy pretend play like playing house or doctor, and spend more time playing with peers. Taking turns and sharing are still hard and need practice.

🚽Potty training

Signs of readiness include being bothered by or telling you about a wet diaper, staying dry for about 2 hours, and showing interest in the toilet. Many children are out of daytime diapers between ages 2 and 3.

Start by sitting on a potty fully dressed, then sit at regular times (such as after meals), and praise specifically when it works. Don't scold accidents. Night dryness usually comes later than daytime.

It's better to pause during big changes such as a new sibling, a move or starting daycare.

🍽️Eating habits and sleep

Serve three meals and one or two snacks at regular times, and sit down to eat together as a family. The rule that parents decide what and when, and the child decides how much, reduces picky eating and power struggles. Don't let sweet drinks and chips become everyday snacks.

Children aged 3–5 are recommended to sleep 10–13 hours a day including naps. Some stop napping around age 3; moving bedtime a little earlier can help.

🩺Checkups, vaccines and teeth

In Korea there are two infant health checkups in this period (30–36 months and 42–48 months) and one dental checkup (42–53 months). Vision and hearing are asked about alongside the developmental screening, so mention it if your child sits very close to the TV, squints or responds little when called.

A flu vaccine is recommended every year. Remaining shots such as Japanese encephalitis can be checked in the immunization registry.

Use a rice-grain smear of fluoride toothpaste under age 3 and a pea-sized amount from age 3, and finish the brushing yourself.

🏫Daycare, kindergarten and discipline

When children start daycare, an adjustment period with crying, sleep troubles and frequent colds is common. Keeping goodbyes short and picking up at the promised time usually helps within a few weeks. In Korea, children aged 3–5 follow the same national 'Nuri' curriculum in both daycare centers and kindergartens.

Keep rules few and clear, and enforce them the same way every time. Notice good behavior specifically, and respond to dangerous or hurtful behavior with a short 'time-in' (calming down together) or a set consequence. Don't use physical punishment.

🛡️Safety

• Switch to a forward-facing harness seat only after outgrowing rear-facing limits, and always install it in the back seat. In Korea, car seats are legally required for children under 6.
• Use a helmet on scooters and tricycles.
• Put a life jacket on near water and stay within arm's reach.
• Practice saying a parent's name and phone number in case they get lost; in Korea you can also pre-register fingerprints with the police (the 'Safe Dream' program).

💉Vaccines & checkups in this stage

• General checkup 4 — Age 18–24 months
• General checkup 5 — Age 30–36 months
• General checkup 6 — Age 42–48 months
• Dental checkup 1 — Age 18–29 months
• Dental checkup 2 — Age 42–53 months

Korea's Childhood Vaccine Schedule →   Infant and Child Health Checkups →

💬FAQ