How Babies Learn Language

Wondering when your child will start talking? Actually, communication begins the moment your baby enters the world and utters that first cry. In response, you feed, diaper, rock, cuddle, and gently shush your child to meet his or her every need.

Responding appropriately to a baby’s cry is a very inexact science…more like a guessing game, actually. Is he tired? Is she hungry? Does he have a wet diaper? Does she just miss your touch? It can be frustrating for you at times, and it’s no doubt frustrating for baby, too. It might even be the motivation for him or her to begin sharpening the message by acquiring language.

A child acquires language in predictable stages. (Note: Some language-acquisition experts suggest that there are six stages (including the earliest stage of cooing). Other experts describe five stages, starting with babbling. Still others contend that there are four main stages when two multi-word stages are combined. That’s what we’ve presented in this article. No matter the number of stages, a child follows the same predictable path to language learning.)


At about 2 months of age, children begin making vowel sounds that come from the throat, e.g., “ah,” “eh,” and “uh.” By 4 months, as a baby gains more control over the tongue and lips, consonant sounds follow. A hard “g” sound typically comes first, e.g., “ah-goo.”

At 6 (or so) months of age, babbling is an important language milestone. Babbling is officially defined as being when a baby makes and repeats consonant-vowel syllables (ma/ma, da/da, ba/ba). When a child babbles, he or she is signaling a readiness to learn language. So, when your baby says, “ba ba,” or “da da,” for example, figure out what he or she is looking at, and then name it. My son used “be-ah” at various times to mean blanket, bottle, and spaghetti.

One-word stage

A few months before a child says a first true word, he or she starts understanding many of the words being heard. “Bottle,” “mama,” and “dada” are among the first words babies understand.

Then, as baby begins making connections between words and objects—at or around 12 months of age—true language production starts to grow. Baby’s earliest words relate to what he or she best knows and is interested in—”mama,” “dada,” maybe even “kitty!”

It might surprise you to learn that most of your child’s earliest words are somewhat predictable. That’s because of research done over a 30-year period by a team of psychology and language-acquisition experts who studied the origins of communication and language in infants and young children. (See our “What are a Baby’s Most Common First Words?” article to learn more.)

A child’s one-word language stage may start as early as 9 months of age, although it more typically starts at 12 months. Then, it extends through 18 months, when the next language stage begins.

Two-word stage

As a child’s vocabulary grows during the second year, he or she enters the two-word stage. In this stage, two related words are put together to form mini-sentences that provide greater meaning or context, e.g., “Mommy hat” for “Mommy is wearing a hat,” or “Cow grass” for “The cow is eating grass,” or “Daddy cookie” for “Daddy is eating a cookie.”

When your child says mini-sentences, acknowledge him or her and respond gently by saying the full sentence correctly. For example, in response to “Mommy hat,” you might say, “That’s right, Mommy is wearing a hat.”

During the second year, new words often are acquired at a rate of 1-3 per week. By the time a child is 18 months of age, he or she may know as many as 50 words. And, even though a child may produce just 40-50 words, he or she is able to understand as many as 150 words.

Whenever a child is at this stage in language development, listen for and encourage verbs in his or her vocabulary. The first three verbs you’ll likely hear are “eat,” “drink” and “go.” Verb acquisition is significant because it leads to the construction of multiword sentences.

Multiword stage

As you might expect, the multiword stage involves multiword statements. Early on in this stage, a 2-year-old, for example, will leave out most “unimportant” words—unimportant to the child, that is. So, if you asked a child to repeat the sentence “I can see a cow,” he or she likely would repeat it as “See cow.” Or, if the sentence was “Where did Daddy go?” the child might instead say, “Daddy go?”

All that changes, however, when later in this stage an older child begins using more of the “unimportant” words, such as “is,” “was,” “I,” “she,” “that,” “the,” and “a.” Also, verb endings such as “-ed” and “-ing” are increasingly used.

At that point, you might hear a child say, for example:

“She’s gone. Her gone school.”

“I’m having this banana.”

“I tease Mommy. I’m teasing Mommy.”

“He’s kicking a ball. Her climbing up the ladder there.”

“Doggy go arf.”

As a child begins talking regularly, sentences become longer and more grammatically correct.

Between ages 2 and 3, a child goes through a huge language burst. Vocabulary words typically exceed 300, with new words added daily. Two-word phrases grow to three- and four-word sentences. Early four-word sentences consist of nouns and verbs, and include pronouns, adverbs, adjectives, and prepositions.

When your child is learning to express him- or herself through language, talk together as often as possible. For example, ask your child about his or her day; talk about pictures in the book you are reading together; discuss favorite stories or movies. Follow your child’s interest in topics to encourage more back-and-forth exchanges. The more practice your child has, the quicker grammatical errors will disappear, and the faster he or she will master all the sounds used in our rather complex language.