Baby week by week · 18–21 months · 19–20 months: sorting the world

Your baby at 81 weeks

From Brittany Ryan, Founder and Mom of Two

What’s happening at about 18 months

Your toddler may notice categories, matches and differences. They may group objects in ways that make sense to them and enjoy predictable routines. Notice connection this week rather than looking for a performance.

What’s ahead

Simple puzzles, matching and two-part play ideas may become more engaging. Keep following your child's cues and make room for repetition.

A memory to keep this week

A matching pair they noticed

Safety first

Use close adult supervision. Check every item for choking, strangulation, tip-over, water and fall hazards. Keep button batteries, magnets, medicines and household chemicals locked away.

In the app this week

Try this together: Sock match, plus this week's memory prompts, a private journal and your Journey, quick logs for firsts like matched a pair and sorted toys. One simple idea at a time, never 47.

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Guided by: CDC milestones + AAP (HealthyChildren.org) + CPSC, written in Brittany's words.

Every pregnancy and every baby is different. This is general, educational information, not medical advice. If something worries you, check with your provider or pediatrician.

Meet our founder

Brittany Ryan

Founder and Mom of Two

Brittany is a mom of two with a background in early childhood development. Little by Little Together began with a beautiful, blank baby book. Like so many parents, she bought baby books with every intention of filling them; instead, they sat in a closet while life kept moving. So she built a personal assistant for parenthood that tells you what matters right now, offers one simple idea at a time, and keeps your story safe.

“You don’t have to remember everything at once. Little by little, there is a story worth keeping.”

Read Brittany's story

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