Speak with your baby in a certain way, new research shows, and your baby is far more likely to pick up on language. The difference is big -- more than double the vocabulary by age 2.
Glad you asked, because "how" is what Zero to Five is all about. Three things: Speak in a sing-songy voice. Talk with your baby one-on-one. And engage baby in a conversation about whatever's going on with the two of you at the moment. (Who can think of a catchy mnemonic for this?)
1. Speak in a sing-songy voice
You know that bright, sing-songy voice people tend to get around babies? It's called parentese. Do that.
"I'm not doing any baby talk with my newborn," some parents say. "Babies aren't dumb! I'm going to speak to my baby like any other smart person."
If you define "baby talk" as making up nonsense words and sounds, good news: Parentese is not the same as baby talk. In parentese, you're using actual words and sentences. You just say them in a sing-songy way.
It sounds like this:
To your significant other you might say: Morning. Hope you made coffee?
To your baby you would say: Oh good morn-ing! I bet yoouuu could use a new diiiiaper!
Parentese is slower. Each vowel and word becomes more distinct, which makes them they're easier for baby to discern. The pitch is higher, which matches the limited range of a baby's vocal tract.
Speaking this way helps your baby pick out and imitate parts of language. It's helpful for about the first 18 months.
In the new study, led by Nairán Ramírez-Esparza and Patricia Kuhl, researchers wanted to know to what extent parentese helps babies develop language. They had a hunch that how you talk with your baby is more important than how much.
The researchers recorded 26 families' conversations in their homes. (Usually families are brought into a lab, a less natural setting.) They recorded 8-hour stretches on each of four days. (The unobtrusive recordings were courtesy of LENA, a lightweight recorder that snaps into a shirt pocket and comes with speech-analysis software.) So the researchers had access to interactions that researchers usually don't get, plus the ability to study the social context of each interaction.
The team looked at whether the babies heard standard adult speech or parentese. They looked at what happened if one adult was talking with the baby vs. more than one adult at a time.
Babies who heard more "one-on-one parentese" shot ahead of the others in language development. Around age 1, they babbled more than babies who heard less one-on-one parentese. When the tots turned 2, parents checked off a list of 680 words (a standard inventory) to report how many words their children spoke.
Babies who had heard the most one-on-one parentese had a much bigger vocabulary than those who had heard the least: 433 words vs. 168 words.
2. Talk one-on-one
Language learning was more effective when one adult was speaking to one child. "Parentese is much better at developing language than regular speech, and even better if it occurs in a one-on-one interaction," Ramírez-Esparza said.
Talk directly to your baby. If baby simply overhears someone talking, that doesn't provide the same boost in vocabulary or language proficiency. Neither does playing audio or video of someone talking. The brain is electrified by face-to-face interaction, Kuhl has shown. The presence or absence of that social connection, she argues, determines whether a baby's brain is open or closed to learning language.
3. Engage in a conversation
Rather than talking nonstop at your child, you want to snuggle in close and have a conversation with baby about whatever you're doing. "It's not just talk, talk, talk at the child," Kuhl said. "It's more important to work toward interaction and engagement around language. You want to engage the infant and get the baby to babble back. The more you get that serve and volley going, the more language advances."
Sounds good. But, uh, newborns just seem to lie there, looking around. Holding a conversation with them can feel awkward to new parents. So what do you talk about? Here are a few ideas:
Be a tour guide
I'm not naturally very talkative, so it's been very helpful for me to think of myself as a tour guide. I talk about the things my baby sees and seems interested in. (Gazing at something is the main way newborns communicate what they're interested in.) "This is brick. It's a deep red color. It feels rough, doesn't it? Brick." I explain the things that are about to happen to my baby. "Let's put on your shirt now. Right arm in the right sleeve..." For more examples, see the tips "Talk to your baby a ton" and "Include baby" in my book, Zero to Five: 70 Essential Parenting Tips Based on Science.
Make it part of your bedtime routine to tell your baby the story of her day. Some people are great at spinning tales, but you don't have to be. Your story could go, "Once upon a time, there was a little baby named Baby. In the morning, she drank some milk. And then her daddy changed her diaper and put on her clothes. She wore a green shirt with a bunny. Then Baby and Daddy went for a walk in the warm fall sun. They saw red leaves and yellow leaves and green leaves. Daddy was really hoping Baby would fall asleep. For lunch, the daddy ate some soup. Baby held onto a big carrot and waved it around a little bit. And then it was time for sleep." The end!
I talk in Zero to Five about how to read together based on ages and stages. But here's one example that reaches across age groups: Give a dramatic reading, with different voices, big expressions, and gestures. When a bee goes "buzz!" you can make the sound and come in close to land a kiss. When a character goes fast or slow, you can use your fingertips to crawl or run up baby's belly.
So how is all of this a conversation instead of a monologue? Cooing, gazing, and eventually pointing are your baby's side of the conversation. You want to leave space for these things and respond to them.
It may feel strange at first, talking so much with someone who doesn't talk back. But the results speak for themselves.