D3.2 Brown’s Five stages of Language Development Theory

Who is Roger Brown?

Acknowledged as the founder of developmental psycholinguistics (study of the relationships between linguistics and psychological processes) and as a pioneer in the study of how children acquire language.

What did Brown believe?

He agreed with Chomsky that children have an innate ability to learn language.

• He believed that language acquisition was a maturational process (developing as you grow)

• He believed that children are encouraged to learn language by hearing the speech of adults

• He used Chomsky’s linguistic theory to predict the stages of children’s language acquisition

What did Brown propose?

A five stage model that predicts pathways of normal expressive language development (expressing your wants and needs through verbal or nonverbal communication).

• A detailed, observable description of the stages children go through as they develop their language skills and grammar

What did each of the stages Brown proposed have?

An Mean Length of Utterance (MLU range).

• The number of morphemes (smallest unit of meaningful range) contained within a word

What is a morpheme?

The smallest unit of meaning in a language that can’t be divided further without losing its meaning.

• For example: "cats" has two morphemes, /kæt/ and /s/ (or ‘cat’ and ‘s’)

• “Unbreakable” has three morphemes, "un-break-able"

What are free morphemes?

These stand alone and have meaning.

• E.g. book, dog, run, happy, school

• Each of these words has meaning by itself

What are bound morphemes?

These can’t stand alone and must be attached to another word.

• -s (as in dogs) → means more than one (plural)

• -ed (as in jumped) → means past tense

• -un (as in unhappy) → means “not”

• -re (as in redo) → means “again”

What is stage 1 of Brown’s five stages of language development?

• Age: 12-26 months

• MLU: 1.0-2.0

• Morphological/Grammatical structure: Single words or two word phrases

• Examples of word: ‘What(‘s) that?’ ,‘Why?’, Yes/No questions, Wh- questions, 1-3 word sentences

What is stage 2 of Brown’s five stages of language development?

• Age: 27-30 months

• MLU: 2.0-2.5

• Morphological/Grammatical structure: Start to use the "-ing” verb ending, prepositions like “in” and “on” and regular plural “-s”

• Examples of word: Running, jumping, cats

What is stage 3 of Brown’s five stages of language development?

• Age: 31-34 months

• MLU: 2.5-3.0

• Morphological/Grammatical structure: Learn possessive (“daddy’s shirt) irregular past tense verbs (“I fell down”)

• Examples of word: Questioning, e.g. ‘Is she sick?’, interrogative reversals (inverting the normal subject-verb word order to form questions), increases in length due to uses of auxiliaries, nouns and phrases

What is stage 4 of Brown’s five stages of language development?

• Age: 35-40 months

• MLU: 3.0-3.75

• Morphological/Grammatical structure: Master articles (“a”, “the”) and the regular past tense verb ending (“he walked”), Indirect or embedded Wh- Qs, object complements (a noun, pronoun, or adjective that follows a direct object in a sentence)

• Examples of word: ‘I made her happy’, ‘She carried’

What is stage 5 of Brown’s five stages of language development?

• Age: 41-46 months

• MLU: 3.75-4.5

• Morphological/Grammatical structure: Refine language, coordinates simple sentences locative, “And” as main conjunction, begin to use contractions (shortened words formed by combining two words)

• Examples of word: ‘We sing’ ,’they listen’ and contractions - “Do not” → “Don’t”, “We are” → “We’re”