Parents often notice speech delay before anyone else does. The child who is not saying as many words as a friend's child of the same age, or who is not combining words when the expected age has passed, prompts concern that is sometimes dismissed and sometimes overreacted to. Getting it right – knowing when to watch and wait, when to refer early, and when to act urgently – depends on understanding what different types of delay mean.
Speech and language development is one of the most important early childhood indicators: language underpins learning, social relationships, and behaviour. A child whose language is delayed is at higher risk of reading difficulties, emotional and behavioural problems, and social exclusion if the delay is not identified and supported.
Healthbooq (healthbooq.com) covers language development and speech delay in young children.
Key Language Milestones
Language development follows a broadly predictable sequence, with considerable normal variation. Key referral benchmarks used in the UK include:
By 12 months: babbling with consonant sounds (ba, da, ma); responding to their own name; pointing to draw attention to things; first words appearing.
By 18 months: at least 10-20 words with meaning; understanding and following simple instructions ("get your shoes," "give it to me").
By 24 months: at least 50 words; beginning to combine two words ("more milk," "daddy go"); strangers should be able to understand around 50% of what the child says.
By 3 years: three-word sentences; vocabulary expanding rapidly; strangers should be able to understand around 75% of what the child says; asking "why" questions.
By 4 years: longer sentences with grammar emerging; telling stories; intelligible to strangers in most contexts.
Types of Speech and Language Delay
Late talker: a child who is delayed in expressive language (the words they produce) but has good comprehension, good social communication (eye contact, pointing, joint attention), and normal play. Many late talkers catch up between ages 2 and 3 without intervention, particularly if they are boys, have a family history of late talking, and have strong comprehension. Around 50-70% of late talkers at age 2 catch up by school age; the remainder go on to have persisting language difficulties.
Developmental Language Disorder (DLD): DLD affects around 7% of children and is a persisting difficulty with language that is not explained by hearing loss, autism, intellectual disability, or other known cause. Children with DLD struggle to learn and use language, have difficulty with grammar, word-finding, narrative, and sentence comprehension. DLD does not resolve without support and requires speech and language therapy, school-based language support, and appropriate SEND provision. The RADLD (Raising Awareness of DLD) campaign has significantly increased awareness among teachers and parents.
Language delay secondary to hearing loss: any degree of hearing impairment can cause language delay. Undetected mild-moderate hearing loss (which may have been missed on newborn screening, particularly if fluctuating due to glue ear) is a common and easily addressed cause. Audiological assessment is mandatory.
Language delay associated with autism spectrum disorder: children with ASD often have delayed language, but the distinguishing features are social-communication difficulties that go beyond language – reduced joint attention, limited pointing, reduced response to name, limited imitation, and restricted or repetitive behaviours. These may be present even before significant language delay.
Assessment
A thorough assessment of a child with language delay includes: detailed history (onset, progression, parental concern, family history of language or reading difficulty); hearing test (referral for formal audiological assessment, not just a GP assessment); observation of comprehension as well as expression; assessment of social communication and play; and SLCN (speech, language and communication needs) assessment by a speech and language therapist (SLT).
The CHAT (Checklist for Autism in Toddlers) and its derivatives screen for social-communication features. The BSID (Bayley Scales of Infant and Toddler Development) and PLS (Preschool Language Scale) are used in formal assessment.
Red flags requiring urgent referral at any age: no babbling by 12 months; no words by 16 months; no two-word phrases by 24 months; loss of language that was previously present (regression); concerns about social communication, eye contact, or responsiveness to name.
Getting Help
Parents can self-refer to NHS speech and language therapy services in most areas of England, or can ask their health visitor or GP for a referral. The Talking Point website (ican.org.uk/i-cans-talking-point) provides age-by-age guidance and helps parents judge whether their child's development is on track.
Key Takeaways
Speech and language delay is one of the most common developmental concerns in early childhood, affecting approximately 10% of children at age 2. The distinction between 'late talkers' (children who are delayed in early language production but who catch up without intervention), Developmental Language Disorder (DLD, previously called Specific Language Impairment), and language delay secondary to another condition (hearing loss, autism spectrum disorder, intellectual disability) is clinically important because the prognosis and intervention differ considerably. Hearing loss must be ruled out in every child with language delay. Late talkers with good comprehension, pointing, play, and social interaction have a better prognosis than those with comprehension difficulties or co-occurring social-communication concerns. Speech and language therapy is effective and early referral produces better outcomes.
