Talking, babbling and first words

Language is the domain where the environment makes the largest measurable difference, and the interventions are conversational rather than educational.

The sequence

Approximate, with wide variation.

From birth: preference for human voices and for the language heard in pregnancy.

Around six to eight weeks: cooing, vowel sounds.

Around three to four months: laughing, a wider range of sounds, taking turns in vocal exchanges.

Around six months: babbling with consonants, repeated syllables.

Around nine to ten months: varied babble that sounds like the rhythm of speech, responding to name, understanding "no".

Around twelve months: one or two words used meaningfully, understanding simple instructions, pointing.

Around eighteen months: a growing vocabulary, commonly tens of words, following simple directions.

Around two years: two-word combinations, and a vocabulary that expands rapidly.

Understanding consistently runs ahead of production, which is why a child who says little may understand a great deal.

What matters most

Serve and return.

The interaction in which a baby vocalises or gestures and an adult responds contingently is the mechanism by which language develops, and it is more important than the quantity of words a child hears in isolation.

Research on conversational turns has found them more strongly associated with language outcomes and with brain activity in language regions than raw word counts.

Which means responding to babble as though it were conversation, pausing for a reply, and following the child's attention rather than directing it.

Practical things that work

Narrate what you are doing throughout the day.

Name objects the child is looking at, rather than what you want them to look at.

Get face to face, so they can see your mouth.

Expand what they say: if they say "dog", say "yes, a big dog".

Repeat and recast rather than correct — if they say "dat", respond "that's a cat, yes".

Read together daily from early on, with picture books, pointing and talking about the pictures rather than only reading the text.

Sing and use rhymes, which support the rhythmic and phonological aspects.

Leave pauses, which is the thing adults do least and which invites a turn.

And reduce background noise, particularly television, which reduces the amount and quality of adult–child talk in a room.

Screens

Where the evidence is reasonably clear for infants.

Children under around eighteen months to two years do not learn language effectively from screens, a phenomenon described as the video deficit.

Guidance in most countries advises against screen media for this age other than video calling with a real person, which involves genuine interaction.

The larger effect may be displacement: screen time reduces conversational turns and reading time, which are the things that build language.

For older children, co-viewing and talking about what is on screen substantially changes what they get from it.

Bilingualism

Where a great deal of unhelpful advice circulates.

Raising a child with more than one language does not cause language delay.

Bilingual children may have a smaller vocabulary in each individual language early on while having a comparable or larger total vocabulary.

Mixing languages within a sentence is normal and is not confusion.

Parents should speak the language they are most fluent and comfortable in, since the quality of interaction matters more than which language it is in.

Advice to abandon a home language in favour of the majority language is not supported by evidence and carries real family and cultural costs.

Hearing

The first thing to check with any language concern.

Newborn hearing screening does not rule out hearing loss acquired later, and glue ear — persistent fluid in the middle ear — is extremely common in early childhood and causes fluctuating hearing loss that affects speech.

Signs: not responding to sound, not turning to their name, speech that is unclear, needing things repeated, turning up volume, and recurrent ear infections.

Any parental concern about hearing warrants a test, at any age, without exception.

When to seek assessment

Practical thresholds.

No babbling by around nine months.

No response to name or to sound at any age.

No words by around eighteen months.

No two-word combinations by around two years.

Speech that is very difficult for family to understand at two and a half, or for strangers at three.

Not pointing to show or share interest by around eighteen months.

Loss of language previously acquired, at any age, which always warrants prompt assessment.

And parental concern, which is a valid reason on its own — speech and language therapy is more effective when started early, and services in many places accept self-referral.

General information only, not medical advice. Consult your health visitor, a speech and language therapist or a qualified clinician about language concerns, and request a hearing test if you have any doubt.