What is ‘parentese’? How we talk to babies has a dramatic effect on their future vocabulary

She’s up from her nap, fed and ready to go. Those eyelashes bat and those rosebud lips burble as she sings and coos and tells us all about it. And we bah bah bah and boo boo boo right back. It’s what we do. We think we are having fun, but what is really going on is so important for how our babies learn to communicate with us. How babies hear language has a big impact on how they learn it.

But going beyond baby talk, making simple sounds and noises, research shows that talking directly to infants, using a distinct form of speech called ‘parentese’—grammatical speech that involves real words—is powerful for fostering communication down the line.

What is parentese?

Characterized by higher pitch, slower tempo and exaggerated tones, and containing sounds that are clearer, longer and more distinct from one another, parentese sounds happy and is usually accompanied by our wide eyes and big smiles; this attracts our little one’s attention, helping them tune in and respond. They try to imitate us through their cooing and burbling. Engaging in this back and forth, our babies learn how to form sounds and string them together.

“We now think parentese works because it’s a social hook for the baby brain—its high pitch and slower tempo are socially engaging and invite the baby to respond,” says Patricia Kuhl, a University of Washington neuroscientist, in a statement.

Parentese is natural. No matter what language or culture, around the world babies analyze words and absorb the phonetic elements that help them discriminate between and remember sounds. In a study out of the University of Washington, it was demonstrated that babies are so good at analyzing parentese that by the time they are 5 months old, they are beginning to produce the three vowel sounds common to all human languages—”ee,” “ah” and “uu.”

Why parentese works to foster language

Our early cooing and boo-booing activate the Language Acquisition Device (LAD) in their brain. Thought to account for our instinctive ability to acquire and produce language, the LAD is where what we hear is processed and what we vocalize and repeat is committed to memory as neural networks are created.

Naturally, babies have been found to prefer parentese over standard speech.

In a study at Boston University, 7‐ and 8‐month‐old babies were presented with two new words, one said in parentese and the other in regular speech. The next day the babies were tested to determine if they could distinguish these words in a sentence. The results showed that the babies were able to recognize the words spoken using parentese better than those using regular speech—and the babies remembered them longer.

But don’t worry that your kiddo will head off to kindergarten talking like a baby, mama. A 2023 study found that parents’ consistent use of parentese in infancy was a strong predictor of language complexity and conversational turn-taking between children and adults at kindergarten entry.

As babies grow older, the clear, hyper-articulated characteristics of parentese are less important for language acquisition. Babies naturally migrate from parentese to regular speech as their vocabularies and abilities advance—and we naturally help them along by innately decreasing our use of parentese and increasing our use of regular speech over time.

These effects have been shown to persist and have a positive impact on language learning in toddlers as well. Children who get the highest amount of parentese as babies produced an average of 400 more words at 33 months than children with the lowest amount of parentese.

Bottom line: The key to teaching your babies to talk is the same as fostering a strong attachment—maintaining that back and forth engagement strengthens babies’ bonds and brains alike.

A version of this story was originally published on Jan. 28, 2021. It has been updated.