Bilingual Speech Development: What Parents Should Know
Many parents raising bilingual children wonder “Will learning two languages confuse my child?” or “Why does my child say a sound differently in each language?”. The good news is that there is currently growing research in bilingual speech development as it is very much normal in many countries like Malaysia, Hong Kong, India etc.
Here’s what research tells us about how children acquire speech sounds across different languages and what it means for bilingual families.
Speech Sound Development Across Languages
Children all over the world go through similar early stages of speech development. Regardless of language, the very first sounds mastered are usually:
Nasals: /m/, /n/
Plosives: /p/, /b/, /t/, /d/
From there, development starts to reflect the unique phonological structure of each language.
Cross-Linguistic Variations
Languages differ in the types of sounds they use, how complex their word structures are, and the size of their sound inventories. This affects when and how children master certain sounds.
Consonant clusters: English has tricky combinations like “str” (street), which are acquired later. Languages like Spanish, with simpler clusters, see earlier mastery.
Phoneme inventory: English has a wide range of sounds, which may lead to longer timelines for full mastery compared to languages like Italian or Spanish.
Examples from Different Languages
English: Children usually master sounds like /m/, /p/, and /b/ by age 3. Trickier sounds such as /s/, /ʃ/ (“sh”), /r/, and /l/ may not be fully mastered until ages 4–7.
Spanish: With simpler rules, children may acquire sounds like /s/ and the trilled /r/ earlier than English speakers.
Mandarin: Dental fricatives like /θ/ (“think”) and /ð/ (“this”) don’t exist in Mandarin. So Mandarin-speaking children learning English often substitute:
/θ/ → /s/ (“think” → “sink”)
/ð/ → /d/ or /z/ (“this” → “dis” or “zis”)
These substitutions are a normal part of second-language development.
What About Bilingual Children?
Bilingual children may show a slightly different path compared to monolingual peers:
Exposure matters: A child may master sounds in one language earlier if they hear and use that language more often.
Influence across languages: Patterns from one language may “spill over” into the other—for example, a child might use Spanish sound patterns when speaking English.
Timing: Research suggests bilingual children may take a little longer to master certain sounds because they are learning two systems at once. This is not a disorder—it’s part of the process.
Key Milestones
Research across 27 languages shows that by around 5 years of age, most children can:
Correctly produce over 90% of consonants in their languages
Use sounds in an adult-like way, even if some later-developing sounds are still refining
Why This Matters
Understanding that speech development looks different across languages helps parents and professionals set realistic expectations. For bilingual children, what may look like a “delay” is often just part of the natural process of managing two sound systems.
At Little Birds, we celebrate bilingualism as a gift. Supporting both languages helps children connect with family, culture, and identity—while building strong communication skills.
Final Thoughts
If you’re raising a bilingual child, remember:
Differences in sound development across languages are normal.
Substitutions or “mix-ups” don’t mean confusion.
Most children will master their sound systems by around age 5.
If you have concerns, a speech pathologist trained in bilingual assessment can help distinguish between a difference and a true disorder.
Bilingualism doesn’t hold children back—it builds bridges.
👉 Want support for your child’s bilingual journey? Our team at Little Birds Allied Health is here to help. Contact us today.
👉 Are you a clinician seeking support with bilingual assessment? Our team at Little Birds Allied Health is here to help. Contact us today at s.yeung@littlebirdsspeech.com
