Children produce their first recognizable words, typically naming caregivers, familiar objects, and social routines. Vocabulary is limited to around 1-10 words, with heavy reliance on context and gesture.
What they say
mama
mama
Mommy
Often among the very first words; may initially be used broadly for any caregiver
no
no
No
One of the earliest function words; used for refusal and negation
ba
ball
Ball
Phonologically simplified; consistent use with pointing establishes reference
Revealing errors
dada→(context-specific name)
Daddy (or any man)
The child is testing word-referent mappings — "dada" may initially be applied to any adult male, revealing hypothesis-driven learning about word meaning
14-20 monthsTwo-Word Stage
Children combine two words to express basic semantic relations: agent-action, action-object, possessor-possessed, and entity-location. Function words (articles, prepositions, auxiliaries) are absent — this is "telegraphic" speech.
What they say
mommy sock
mommy sock
Mommy's sock / Mommy, put on my sock
Classic two-word combination from Brown (1973); ambiguous between possession and request
more milk
more milk
I want more milk
Recurrence relation; "more" is one of the most productive early combiners
doggy go
dog go
The dog is going / went
Agent-action relation with no tense marking or articles
Revealing errors
no bed→I don't want to go to bed
I don't want bed / No bed
The child places "no" before a content word to negate — an early negation strategy before auxiliary verbs or "not" are acquired
allgone milk→The milk is all gone
The milk is finished
The child treats "allgone" as a single predicate word applied to an object — a creative proto-sentence before copula or articles emerge
20-30 monthsGrammar Explosion
Rapid morphological growth corresponding to Brown's Stages I-II (MLU 1.75-2.25). The first grammatical morphemes appear: present progressive -ing (without auxiliary), prepositions 'in' and 'on', and regular plural -s. Children begin producing 3-4 word utterances with emerging word order.
What they say
doggy running
dog run-PROG
The dog is running
Present progressive -ing without auxiliary "is" — the earliest acquired of Brown's 14 morphemes (19-28 months)
usually taught: early
two shoe
two shoe
Two shoes
Numeral present but plural -s not yet consistent; number concept precedes morphological marking
usually taught: early
kitty in box
kitty in box
The kitty is in the box
Preposition "in" emerges early (27-30 months); no articles or copula yet
me want cookies
1SG want cookie-PL
I want cookies
Plural -s emerging on nouns; pronoun case not yet adult-like ("me" for "I")
usually taught: early
Revealing errors
foots→feet
Feet
The child has learned the regular plural rule (-s) and applies it to an irregular noun — evidence of productive rule learning, not memorization
he go park→He went to the park
He went to the park
Multiple omissions are typical at this stage: no past tense marking, no preposition "to", no article — the child preserves content words and word order
2.5-3.5 yearsComplex Sentences
Brown's Stages III-IV (MLU 2.5-4.0). Irregular past tense forms appear (went, came, broke), possessive 's emerges, articles (a/the) become consistent, and the copula appears. Children begin asking wh-questions and using basic clause combining. This is the peak period for overgeneralization errors.
What they say
that's mommy's hat
that-COP mommy-POSS hat
That is mommy's hat
Contractible copula and possessive -'s both emerging (Brown morphemes #6-7)
usually taught: early
usually taught: early
I went to the store
1SG go.PST to DEF store
I went to the store
Correct irregular past tense; articles and prepositions now present
usually taught: early
usually taught: early
where the doggy is?
where DEF dog COP
Where is the dog?
Wh-question without subject-auxiliary inversion — a characteristic intermediate form
usually taught: early
Revealing errors
I goed to the park→I went to the park
I went to the park
Classic U-shaped development: the child previously said "went" correctly, but after learning the regular -ed rule, overapplies it to irregular verbs — evidence of productive grammatical knowledge (Pinker 1999)
mouses→mice
Mice
Overgeneralization of the regular plural -s rule to an irregular noun, parallel to verb overregularization — the child knows the rule but has not yet memorized all exceptions
3.5-5 yearsRefinement
Brown's Stage V and beyond (MLU 4.0+). The remaining Brown morphemes are mastered: regular past -ed, third person singular -s, contractible and uncontractible auxiliaries. Children produce complex sentences with relative clauses, coordination, and embedded complements. Overgeneralization errors gradually decline as irregular forms are consolidated in memory.
What they say
she walks to school every day
3SG.F walk-3SG to school every day
She walks to school every day
Third person singular -s — one of the LAST morphemes mastered (Brown #10, typically 43-46 months), despite being taught in week 1 of most ESL courses
usually taught: early
the boy who was crying is okay now
DEF boy REL COP.PST cry-PROG COP okay now
The boy who was crying is okay now
Relative clause with auxiliary "was" — complex embedding achieved by age 4-5
Double-marking: the child applies -ed to an already irregular past form, showing awareness of both the irregular stem change AND the regular rule — the two systems compete before irregulars fully consolidate
her went outside→she went outside
She went outside
Pronoun case errors persist — "her" used in subject position; nominative/accusative distinction is still being sorted out
5+ yearsNear-Adult Grammar
Children acquire the final complex constructions: full passive voice, multi-clause conditionals, and discourse-level cohesion. Overgeneralization errors are rare. Pragmatic and stylistic refinement continues — children learn to adjust register, use indirect speech, and understand sarcasm and figurative language.
What they say
the window was broken by the ball
DEF window AUX.PST break.PTCP by DEF ball
The window was broken by the ball
Full agentive passive — one of the last constructions acquired (typically age 5-6+)
usually taught: mid
if it rains we can't go outside
if 3SG.N rain.3SG 1PL can-NEG go outside
If it rains, we can't go outside
First conditional with present tense protasis; modal verb negation
the car got fixed by my dad→the car was fixed by my dad
The car was fixed by my dad
The child uses colloquial "got" passive instead of formal "was" passive — not strictly an error but reflects register development; the formal passive takes longer to fully master
Sources for English
The grammatical descriptions on this page are informed by the following published reference and descriptive grammars. Grammatical facts themselves are not subject to copyright; the scholars who documented them deserve attribution.
Huddleston, R. & Pullum, G.K. (2002). The Cambridge Grammar of the English Language. Cambridge University Press. ISBN 978-0-521-43146-0.
Quirk, R., Greenbaum, S., Leech, G. & Svartvik, J. (1985). A Comprehensive Grammar of the English Language. Longman. ISBN 0-582-51734-6.
Biber, D., Johansson, S., Leech, G., Conrad, S. & Finegan, E. (1999). Longman Grammar of Spoken and Written English. Longman. ISBN 0-582-23725-4.
Carter, R. & McCarthy, M. (2006). Cambridge Grammar of English: A Comprehensive Guide. Cambridge University Press. ISBN 978-0-521-58846-1.
Swan, M. (2016). Practical English Usage. 4th ed. Oxford University Press. ISBN 978-0-19-420243-5.