Genetic_disorders

Newborn

Reflexive communication

Cries, movements, facial expressions.

A newborn baby sleeps on a white blanket.

Inna Astakhova/ ShutterStock

2 months

A range of meaningful noises

Cooing, fussing, crying, laughing

3–6 months

New sounds

Including squeals, growls, croons, trills, vowel sounds

A mother lifts her baby with two hands and they smile at each other.

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6–10 months

Babbling

Including both consonant and vowel sounds repeated in syllables. Examples: ma-ma-ma, da-da-da, ba-ba-ba

An Asian baby boy with his hands behind his head.

Xiaojiao Wang / Shutterstock

10–12 months

Comprehension of simple words

Speech-like intonations; specific vocalizations that have meaning to those who know the infant well. Deaf babies express their first signs; hearing babies also use specific gestures (e.g., pointing) to communicate

A baby girl in a red floral dress smiles with her hands raised up.

Marlon Lopez MMG1 Design / Shutterstock

13–18 months

Slow growth of vocabulary

Up to about 50 words. Can learn names of caregivers, siblings, pets, and favorite foods, as well as refer to elimination. Examples: mama, nana; pee-pee, doo-doo

A man watches his daughter play with some plastic toys and smiles at her.

Monkey Business Images / Shutterstock

18 months

Naming explosion

Three or more words learned per day.
Much variation: Some toddlers do not yet speak

21 months

First two-word sentence

Examples: More juice. Baby cry.

24 months

Multiword sentences

Half the toddler’s utterances are two or more words long. Example: Mommy read book

A toddler holds a flower and stands next to his father in a green meadow.

pavla / Shutterstock