Component 2: Child Language — How Children Understand the Structure of Words (Morphology)
Welcome to your complete revision guide for Morphology in Child Language Acquisition! If you have ever listened to a four-year-old proudly announce that they "runned to the park" or that they have two "foots", you have witnessed morphology in action. In this chapter, we will explore how children figure out the building blocks of words, why their "mistakes" are actually brilliant signs of learning, and how to write top-band answers for your Pearson Edexcel AS English Language (8EN0) exam.
Don't worry if linguistic terms feel intimidating at first. We will break down every concept step by step with clear definitions, everyday analogies, and exam tips.
1. The Building Blocks: What is Morphology?
Morphology is the study of the structure of words and how words are formed from smaller units of meaning called morphemes.
A morpheme is the smallest meaningful unit of language. You cannot break a morpheme down any further without losing its core meaning.
Free vs. Bound Morphemes
Think of morphemes like building bricks. Some bricks can stand all by themselves, while others must stick to another brick to make sense:
1. Free Morphemes: These units can stand alone as independent, meaningful words.
Examples: dog, walk, play, quick, chair.
2. Bound Morphemes: These units cannot stand alone as independent words. They must be attached (affixed) to a free morpheme (a root or stem) to create meaning.
Examples: prefixes like un-, re-, dis-; suffixes like -s, -ed, -ing, -ly, -ness.
Analogy to remember: A free morpheme is like a mobile phone (it works completely on its own). A bound morpheme is like a phone charger (it is only useful when plugged into a phone!).
Inflectional vs. Derivational Morphology
When children attach bound morphemes to words, they do so for two distinct purposes. Examiners specifically look for your ability to distinguish between them:
A. Inflectional Morphemes (Grammar Adjusters):
These are affixes added to a word to modify its grammatical function (such as tense, number, aspect, possession, or comparison) without changing the word's fundamental word class (part of speech).
Key English inflectional morphemes include:
• Plural marker: -s / -es (e.g. cat \( \rightarrow \) cats [both are nouns])
• Regular past tense marker: -ed (e.g. jump \( \rightarrow \) jumped [both are verbs])
• Present participle / progressive aspect marker: -ing (e.g. run \( \rightarrow \) running)
• Third-person singular present tense marker: -s (e.g. she walk \( \rightarrow \) she walks)
• Possessive marker: -'s (e.g. mummy \( \rightarrow \) mummy's)
• Comparative and superlative markers: -er, -est (e.g. fast \( \rightarrow \) faster \( \rightarrow \) fastest)
B. Derivational Morphemes (Word Builders):
These are affixes added to a base or root word to create an entirely new lexical item, frequently changing the word class or significantly altering its meaning.
• Verb \( \rightarrow \) Noun: teach + -er \( \rightarrow \) teacher
• Adjective \( \rightarrow \) Noun: happy + -ness \( \rightarrow \) happiness
• Meaning change: happy + un- \( \rightarrow \) unhappy
Child Word-Formation Processes
Young children are creative linguists. When they lack a specific vocabulary word, they use morphological processes to invent new ones:
• Compounding: Joining two free morphemes together to name a new object (e.g. adult words like teapot, or child innovations like spoon-fork or car-man).
• Conversion (Zero-Derivation): Shifting a word from one word class to another without adding an affix (e.g. converting the noun broom into a verb: "I'm brooming the floor").
• Blending & Clipping: Merging parts of two words together or shortening existing words.
Key Takeaway: Free morphemes stand alone; bound morphemes attach to other words. Inflectional morphemes change grammar (tense/plural), while derivational morphemes create new words or change word classes.
2. How Children Learn Rules: Errors, Overgeneralisation, and the U-Shaped Curve
Virtuous Errors
When a child says "I falled over" or "look at the mouses", everyday listeners might call it a mistake. In linguistics, we call this a virtuous error.
A virtuous error is a non-standard utterance that demonstrates the child is actively grasping and applying systematic underlying grammatical rules, rather than merely copying what adults say. Because no adult says "falled" or "mouses", these utterances prove that language development is generative and creative.
Overgeneralisation (Over-regularisation)
Overgeneralisation occurs when a child takes a regular morphological pattern (such as adding -ed for past tense or -s for plurals) and applies it to an irregular word form.
• Noun plurals: "foots" (instead of feet), "sheeps" (instead of sheep), "mouses" (instead of mice).
• Past tense verbs: "goed" (instead of went), "runned" (instead of ran), "comed" (instead of came), "swimmed" (instead of swam).
The U-Shaped Curve of Morphological Development
A child's mastery of irregular forms does not follow a straight, upward line. Instead, it follows a U-shaped developmental curve consisting of three clear stages:
Stage 1: Direct Imitation and Rote Learning (High surface accuracy)
The young child uses the correct irregular forms (e.g. went, came, feet). However, they do not yet understand the underlying grammatical rule; they have simply memorised these specific individual words by hearing adults use them.
Stage 2: Rule Extraction and Overgeneralisation (Apparent regression / dip in accuracy)
The child figures out the general rule (e.g. add -ed for past tense; add -s for plurals). Excited by this newfound rule, the child applies it everywhere, producing non-standard forms like goed and foots. Although they seem to be making more mistakes than in Stage 1, this stage represents a major cognitive breakthrough: rule discovery!
Stage 3: Mastery and Integration (High accuracy with full rule comprehension)
The child successfully sorts regular words from irregular words. They reliably produce both regular forms (walked, cats) and irregular forms (went, feet), fully understanding exceptions to the general rules.
Key Takeaway: Overgeneralisation is not a failure—it is proof of learning! The dip in accuracy during the U-shaped curve shows that the child has moved from blind imitation to understanding underlying linguistic rules.
3. Landmark Research: Gleason and Brown
Jean Berko Gleason (1958) – The Wug Test
How do we know for certain that children internalise grammatical rules rather than just memorising every word they hear? Jean Berko Gleason answered this in 1958 with one of the most famous experiments in linguistics: The Wug Test.
The Experiment:
Gleason showed children aged 4 to 7 drawings of a fictional, bird-like cartoon creature and used pseudowords (made-up words) that the children could never have heard before. She said:
"This is a WUG. Now there is another one. There are two of them. There are two... [___]."
The Finding:
The children overwhelmingly supplied the word "wugs", correctly attaching the plural bound morpheme /-z/ to a completely new root word.
Why this matters for your exam:
Because wug is an invented word, children could not have learned wugs through imitation or repetition. The Wug Test provides definitive empirical evidence that children extract abstract morphological rules and apply them generatively.
Roger Brown (1973) – The Order of Morpheme Acquisition
Roger Brown conducted a landmark longitudinal study tracking young children's Mean Length of Utterance (MLU). He discovered that children acquire grammatical morphemes in a remarkably consistent, predictable developmental order:
Brown's 10 Key Morphemes (in sequence):
1. Present progressive: -ing (e.g. running, eating)
2. Prepositions: in, on
3. Regular plural: -s (e.g. cats, dogs)
4. Irregular past forms: went, came, saw
5. Possessive: -'s (e.g. mummy's, daddy's)
6. Uncontractible copula: full form of the verb to be acting as the main verb (e.g. "Is it?", "Here I am")
7. Articles: a, the
8. Regular past tense: -ed (e.g. walked, jumped)
9. Third-person regular present: -s (e.g. she walks, he runs)
10. Third-person irregular present: does, has
Exam Application: Notice that -ing appears very early, while regular past tense -ed and third-person present -s develop much later. If you see a young child using -ing perfectly while omitting past tense -ed, you can cite Brown's developmental sequence as theoretical evidence.
Key Takeaway: Gleason's Wug Test proved children apply generative rules to novel words. Brown showed that grammatical morphemes are acquired in a steady, universal sequence.
4. Theoretical Debates: How Does Morphology Develop?
When analysing transcripts in Component 2 (8EN0/02), you must evaluate child data through different theoretical lenses:
1. Nativism / Innateness (Noam Chomsky)
• Core Argument: Children are born with an innate capacity for language called the Language Acquisition Device (LAD) and access to Universal Grammar.
• Morphological Link: Virtuous errors ("goed", "mouses") and the Wug Test are primary evidence for Nativism. Because children produce forms that adults do not model, they cannot be acquiring morphology purely by copying their environment.
2. Behaviourism (B. F. Skinner)
• Core Argument: Language is learned through conditioning, imitation, and positive reinforcement from caregivers.
• Morphological Link: Skinner's model explains why children learn high-frequency irregular forms early via rote imitation (Stage 1 of the U-shaped curve). However, Behaviourism struggles to explain why children later produce overgeneralisations ("breaked") despite never receiving positive reinforcement for them.
3. Constructivism / Usage-Based Approach (Michael Tomasello)
• Core Argument: Language acquisition relies on general cognitive skills, social interaction, and pattern-finding rather than an innate grammar module.
• Morphological Link: Tomasello argues that children start with specific, item-based constructions (memorising individual phrases) and gradually build up schema abstractions through communicative use and pattern detection over time.
5. Examiner Tips & Common Pitfalls to Avoid
To secure top marks in Component 2: Child Language, keep these critical examiner guidelines in mind:
Avoid Pitfall 1: Conflating Morphology with Phonology or Spelling
The Mistake: Calling a spelling error (e.g. writing kat instead of cat) or a pronunciation shift (e.g. saying dat instead of that) a morphological error.
The Fix: Keep them separate! Morphology is strictly about meaningful grammatical units, bound affixes, and word structure.
Avoid Pitfall 2: Treating Overgeneralisation as a "Deficit"
The Mistake: Writing that the child "failed" or "made a bad mistake" when saying "I swimmed".
The Fix: Always frame this as a virtuous error and an indicator of cognitive and morphological rule acquisition.
Avoid Pitfall 3: Name-Dropping Theories in Isolation
The Mistake: Writing a generic paragraph about Chomsky or Skinner without referencing the exam text.
The Fix: Always tie the theorist directly to the exact morpheme in the transcript. (e.g. "The child's use of the overgeneralised inflectional suffix '-ed' in 'eated' supports Chomsky's Nativist theory, as it represents a virtuous error not learned through imitation...").
Avoid Pitfall 4: Generic "Prefix and Suffix" Labels
The Mistake: Simply stating that a child "added an ending".
The Fix: Use accurate terminology: state clearly whether the affix is an inflectional morpheme (marking tense, aspect, or plural) or a derivational morpheme (forming a new lexical item or changing word class).
6. Chapter Quick Review
• Morpheme: Smallest unit of meaning.
• Free Morpheme: Can stand alone as a word (e.g. play).
• Bound Morpheme: Must attach to a root (e.g. -ed, -s, un-).
• Inflectional: Changes grammatical function without changing word class (e.g. walk \( \rightarrow \) walked).
• Derivational: Creates a new word or changes word class (e.g. teach \( \rightarrow \) teacher).
• Overgeneralisation: Applying a regular morphological rule to an irregular word (e.g. "runned", "foots").
• Virtuous Error: A logical error demonstrating active rule internalisation.
• U-Shaped Curve: Imitation (Stage 1) \( \rightarrow \) Overgeneralisation (Stage 2) \( \rightarrow \) Accurate Mastery (Stage 3).
• Jean Berko Gleason (1958): The Wug Test proved children apply rules generatively to novel words.
• Roger Brown (1973): Documented the fixed acquisition order of 10 key morphemes (starting with progressive -ing).