Speech Sound Development Milestones
As a general guide for speech sound development milestones, most children can produce sounds like p, b, m, n, t, d, k, g, h, w, and f clearly by age three, and around 75 to 85 percent of children have mastered nearly all English consonants by age five. If your child is still very hard to understand well past these ages — or if family members and unfamiliar adults regularly struggle to understand them — that’s the point where a proper speech sound assessment is worth having, rather than waiting to see if it resolves on its own.
What’s actually typical for the speech sound development milestones for my child’s age?
Large-scale research reviewing children’s sound development across many languages found that clear, common patterns hold across all of them: early sounds develop from around age two, and most sounds are fully mastered by around age five (McLeod & Crowe, cross-linguistic review of consonant acquisition). More specifically, this research found that plosives, nasals, and glide sounds are typically mastered by around four years old, affricate sounds by around five, liquid sounds like “l” and “r” by around six, and fricative sounds — often the trickiest group, including “s,” “sh,” “th,” and “z” — by around seven. This means it’s genuinely normal for a four or five-year-old to still be working out sounds like “r,” “th,” or “s,” and this alone isn’t cause for concern.
What actually counts as a red flag according to speech sound development milestones, then?
The pattern worth assessing is when a child’s speech remains unclear to familiar listeners well beyond these typical windows — for example, a five-year-old whose parents and siblings still can’t understand large parts of what they say, or a child whose speech is unclear across the board rather than showing difficulty with just one or two of the later-developing sounds. It’s also worth having assessed if your child seems aware that they’re not being understood and becomes frustrated, withdrawn, or reluctant to talk in group settings like kinder or school because of it.
Does this look different for bilingual children? It can, and this is exactly why bilingual milestone charts need some adaptation rather than a straight comparison to English-only norms. Bilingual children are acquiring two sound systems at once, and some sounds that exist differently across Cantonese, Mandarin, and English may take slightly longer to fully settle, or may show cross-linguistic influence from one language to the other. This is a normal part of bilingual speech development, not evidence of a delay — but it does mean an assessment for a bilingual child needs to consider both of their languages together, rather than measuring speech clarity in English alone.
Does this differ for boys and girls, or between siblings? Speech sound development varies from child to child, and some of that variation is completely normal — it’s common for one sibling to sound clearer earlier than another at the same age, without either pattern being a problem on its own. What matters clinically isn’t comparing your child to a sibling or a classmate, but tracking whether your own child’s speech is becoming steadily clearer over time and whether it falls within the broad ranges outlined above. A child who is progressing, even slowly, looks very different clinically to a child whose speech has plateaued or become harder to understand.
What should I do if I’m not sure? Trust what you’re actually noticing day to day. If people outside your immediate family regularly ask you to “translate” what your child has said, or if your child avoids talking in group settings because they’re not being understood, that’s worth having properly assessed — regardless of whether it technically falls within a “normal” age window on paper. A speech pathologist can tell you clearly and quickly whether what you’re hearing is expected for your child’s age and language background, or something worth actively working on.
Where to go from here about speech sound development milestones
If you’re unsure whether your child’s speech is on track, a speech pathology assessment gives you a clear, evidence-based answer rather than a guess — and for bilingual children, an assessment that considers every language they speak, not just English.
To ask a question or book an assessment, complete our service request form and our team will be in touch in English, Cantonese, or Mandarin.
This article is for general education only and is not a substitute for individualised clinical advice from a qualified speech pathologist.
甚麼時候應該擔心孩子發音不清？一份按年齡劃分的語音發展里程碑指南
一般而言，大部分孩子在三歲時已能清楚發出p、b、m、n、t、d、k、g、h、w及f等音，而約75%至85%的孩子在五歲時已掌握幾乎所有英語輔音。如果你的孩子在這些年齡之後,仍然非常難以理解——或家人及不熟悉的成人經常難以聽懂孩子所說的話——這便是值得作正式語音評估的時候，而不是等待看看情況會否自行改善。
我孩子這個年齡,大概正常的發展是怎樣？
一項檢視多種語言兒童語音發展的大型研究發現，各語言之間存在清晰、共通的模式：較早期的發音約從兩歲開始發展，而大部分發音在約五歲時已完全掌握（McLeod & Crowe，輔音習得跨語言回顧）。具體而言，這項研究發現，爆破音、鼻音及滑音一般在約四歲掌握，塞擦音約於五歲，「l」及「r」等流音約於六歲，而摩擦音——包括「s」、「sh」、「th」及「z」等，往往是最困難的一組——則約於七歲掌握。這代表四、五歲的孩子仍在摸索「r」、「th」或「s」等發音,是完全正常的現象,單憑這一點並不需要擔心。
那麼甚麼情況才真正算是警號？
值得評估的模式，是孩子的說話在超出這些典型時間範圍後，仍然難以被熟悉的聆聽者理解——例如一個五歲孩子,其父母及兄弟姊妹仍然聽不懂他大部分的說話內容，或孩子的發音整體上都不清晰，而非只是在一兩個較後期發展的發音上有困難。如果孩子似乎意識到自己不被理解，並因此感到沮喪、退縮，或不願在幼兒園或學校等群體環境中說話，同樣值得作評估。
雙語孩子的情況會否有所不同？ 有可能不同，這正正是雙語里程碑圖表需要作出調整，而非直接與純英語常模比較的原因。雙語兒童同時學習兩套語音系統，某些在廣東話、普通話及英語中發音方式不同的音，可能需要較長時間才能完全穩定下來，或會出現一種語言對另一種語言的跨語言影響。這是雙語語音發展的正常部分，並非遲緩的證據——但這代表為雙語孩子作評估時，需要同時考慮他的兩種語言，而不只是以英語衡量發音清晰度。
男孩和女孩、或兄弟姊妹之間會有分別嗎？ 語音發展因人而異，部分差異完全正常——同齡的兄弟姊妹，其中一人發音較另一人早變得清晰,是常見的情況，兩種模式本身都不算是問題。臨床上真正重要的，並非把你的孩子與兄弟姊妹或同班同學比較，而是追蹤你的孩子的發音是否隨時間持續變得清晰，以及是否落在上述的大致範圍之內。一個持續進步（即使緩慢）的孩子，與一個發音停滯不前或變得更難理解的孩子，臨床上是截然不同的兩回事。
如果不確定,應該怎麼做？ 相信你日常的觀察。如果你直系家庭以外的人經常要求你「翻譯」孩子所說的話，或孩子因不被理解而逃避在群體環境中說話，這便值得作正式評估——不論這在紙面上的「正常」年齡範圍內與否。言語治療師能清楚、迅速地告訴你,你所觀察到的情況，對孩子的年齡及語言背景而言是否屬預期之內，還是值得積極處理。
接下來可以怎樣做
如果你不確定孩子的語音發展是否正常，一個言語治療評估，能給你一個清晰、基於實證的答案，而非憑猜測——對雙語孩子而言，評估亦會考慮他所說的每一種語言，而不只是英語。
如欲提出疑問或預約評估，請填寫我們的服務申請表格，我們的團隊將以英語、廣東話或普通話與你聯絡。
本文僅供一般教育參考之用，不能取代合資格言語治療師的個別臨床意見。