Timing is everything—especially when it comes to language learning. One of the most common questions parents ask is: When should I start introducing a second language to my child? The answer, backed by decades of developmental research, is simple: the earlier, the better.
The Science of the Language Window
According to the Critical Period Hypothesis (Lenneberg, 1967), the human brain is biologically primed to absorb language in the first few years of life. During this "language window," typically from birth to around age 7, the brain is especially receptive to sounds, structures, and vocabulary. In fact, children exposed to a second language early often develop native-like pronunciation and grammar.
A massive 2018 study from MIT (Hartshorne, Tenenbaum & Pinker) involving over 600,000 people confirmed that while language learning ability remains strong until about age 17, the steepest curve for easy acquisition is before age 10. Early exposure maximizes fluency potential.
Babies Are Natural Linguists
Even before they can speak, babies are absorbing the rhythm and tones of language. Research from Patricia Kuhl at the University of Washington shows that babies as young as 6 months old can distinguish between the sounds of multiple languages. This ability begins to narrow if only one language is heard consistently.
What If You Start Later?
It’s never too late to start—but it might take more effort. Older children and even adults can still become fluent in a second language with consistent exposure and practice. The key is to make learning immersive and fun.
Everyday Strategies to Maximize the Window
-
Speak to your baby in your native language, even if your partner speaks another.
-
Use music and story time in both languages.
-
Consider tools like Phoenyx that are designed for playful bilingual interaction from the very beginning.
-
Don’t be afraid of mixing languages—code-switching is a normal part of bilingual development.
The Bottom Line
Start now. Whether your child is 6 months or 6 years old, introducing a second language will give them cognitive, cultural, and emotional advantages that last a lifetime. Your efforts today can unlock a world of opportunities tomorrow.