It’s virtually impossible to be around a baby and not have your voice rise several octaves as you “ooh” and “ahh” over them, and try to get them to respond to you. In a new video, Ms. Rachel brilliantly explains the value of “parentese” and how it differs from typical “baby talk.”

“Parentese” is a form of speech that adults often use when communicating with infants and young children. It involves speaking in a simplified and exaggerated manner, characterized by: high-pitched and sing-song intonation, simplified vocabulary, slow and clear speech, repetition, and facial expressions/gestures.

Ms. Rachel—undoubtedly the best person for the job—demonstrated “parentese” in her latest Instagram post.

“This is not baby talk,” she writes in the caption of her post. “Parentese is shown to boost baby’s language development. It captures the baby’s attention!”

Baby talk is generally a mixture of silly sounds and nonsense words. Parentese is considered to be fully grammatical speech—it involves real words and phrases. You’re just saying them in a different way using elongated vowels and exaggerated tones of voice.

“Something amazing is that we do it naturally across the world,” Ms. Rachel notes. “In a recent study with 18 languages across 6 continents, every one of them did it. We instinctively know to talk to babies differently. Aw.”

A 2018 study showed when parents were coached in parentese, their babies babbled more and had more words by 14 months than those who were not trained. In a speech development study published in 2020 in the Proceedings of the National Academy of Sciences, 48 participating families used some parentese at the start of the study. Babies of parentese-coached parents showed significant gains in conversational turn-taking and vocalizations between 14 and 18 months.

“Children of coached parents produced real words, such as ball or milk, at almost twice the rate of children whose parents were in the control group,” Ferjan Ramirez, the study’s author, said.

Additionally, babies whose parents were coached had an average vocabulary of 100 words compared to the 60 words in the control group.

“Remember to talk to your baby,” Ms. Rachel concludes. “It will help them their whole life! Love you! Also remember, perfection is not the goal. Love is.”