Will two languages delay my baby's speech?

This is the fear I hear most from parents of babies. And it's the one that makes the most parents give up before they even start.

So let's look at it calmly.

Why do people say two languages cause delays?

Because it used to be normal advice. For a long time, families were told to pick one language "so the child isn't confused." Many doctors and teachers trained when that idea was common, and it sticks around.

When my daughter Lia was little, almost everyone around us had an opinion. Our pediatrician never said it officially, but one day he told us:

"You should speak Spanish to your daughter."

"No. She'll learn it on her own."

And she did. Lia actually started talking earlier than most children around her. Her first word was "Papa." In French, of course.

What does the research say?

It says the old advice was wrong.

• Two languages don't harm communication development. Children's Hospital Colorado says it plainly in its guide to raising bilingual children.
• Count both languages. A bilingual child may know fewer words in each language. Add the two together, and the total is the same as or larger than a monolingual child's (Becoming Bilingual).
• This holds for children with extra needs too. Research summarized by Pathways.org shows that children with a language impairment, Down syndrome or autism who grow up bilingual don't have extra communication delays compared with similar children who speak one language.

Here's why the myth survives. A test that only counts Spanish words will make a bilingual child look behind when they aren't. Half of what they know is in the other language.

Is mixing languages a sign of confusion?

No. When a child says "I want una manzana," many adults wince. They shouldn't.

Linguists call it code-switching. Bilingual adults do it all the time. In children, it usually means they're reaching for the word they know best at that moment.

It's a phase. It's not a red flag. What counts is how you react: answer in your language, and slip in the word they were missing.

What actually helps a baby learn to talk?

You, talking to them. A lot.

I know what some parents think: "My baby can't talk back, so what's the point?" I get it. But that's exactly why I never stayed silent with Lia. I told her what I was cooking, what we saw outside, what we'd do next.

The research backs this up. Weisleder and Fernald (2013, Psychological Science) found that speech addressed directly to young children, not talk happening in the background, was linked to stronger language processing and a bigger vocabulary later.

And when your baby coos and you answer, that little back-and-forth already counts as a conversation.

So talk to your baby. In your language. It might feel silly. It isn't.

What do I say to the doctor, or to my in-laws?

Stay calm. They mean well. You're gently correcting an old idea, and calm wins more arguments than anger.

"I appreciate you looking out for her. From what I've read, growing up with two languages doesn't cause speech delays. Kids can know fewer words in each language but about as many overall. Could we look at both languages together?"

"I get why it looks confusing. But mixing is totally normal for bilingual kids. And the more you talk to her, the better it works."

You don't need to win the argument. You just need to keep going.

When should I really worry?

Bilingualism doesn't cause a language disorder. But a bilingual child can have one, just like any child.

If your child isn't speaking much in any of their languages, see a specialist. Ideally one who will assess all of them. Dropping your home language is not the fix. It only takes away language your child was receiving.

I'm a dad and a language teacher, not a speech therapist. This article is not medical advice.

What if the words come, but in the wrong language?

That's a different question, and a very common one. Your child understands you perfectly but answers in the other language. I wrote about it here: My child understands my language but answers in English. What can I do?