LECTURE 4: MORPHOLOGY & SYNTAX DEVELOPMENT

Free vs. Bound Morphemes

• Free Morphemes: Morphemes that can stand alone as words (e.g., dog, play).

• Bound Morphemes: Prefixes or suffixes that must be attached to another word (e.g., -ed, un-, -s).

• Real-Life Example: In the word unbreakable, break is a free morpheme, while un- and -able are bound morphemes.

Overregularization Errors

Applying regular morphological rules to irregular words/exceptions.

• Real-Life Example: A child says "tooths" instead of teeth, or "goed" instead of went. This is actually positive evidence of rule-learning!

Telegraphic Speech (Two-Word Stage)

Early multi-word sentences (around 18 months) that contain content words while omitting grammatical and bound morphemes (articles, prepositions, auxiliaries)

• Real-Life Example: A toddler says "Daddy sit" (Agent + Action) or "Mommy sock" (Possessor + Possession) instead of "Daddy is sitting".

How to Calculate Mean Length of Utterance (MLU)

MLU = Total number of morphemes/total number of utterances

• Real-Life Example: If a child produces 5 utterances containing a total of 15 morphemes, their MLU is 15/5 = 3. An MLU of 3.0 typically indicates Stage III grammatical development (using diverse sentence types)

Rules of Grammar: Descriptive vs. Prescriptive

• Descriptive Rules: The implicit, unconscious grammatical rules that accurately describe a speaker's actual linguistic knowledge. Developmental researchers focus on descriptive rules.

• Prescriptive Rules: Formal rules taught in school regarding "proper" etiquette and education (e.g., avoiding "Me and Tiffany went").

Wug Test (Berko Gleason, 1958)

Demonstrates that children have internalized productive morphological rules rather than just memorized words (e.g., knowing that the plural of a nonsense word wug is wugs)

Overregularization Errors

Applying regular morphological rules to irregular forms (e.g., tooths instead of teeth, falled instead of fell).

Morphemes

The smallest units of meaning in a language (free morphemes are standalone words; bound morphemes include prefixes and suffixes).

Brown’s 14 Grammatical Morphemes

Acquired in a highly regular developmental sequence across English-speaking children (starting with present progressive -ing, prepositions in and on, plural -s, irregular past tense, up to contractible auxiliaries and copulas).

Transition from One-Word Speech

Includes vertical constructions, unanalyzed word combinations ("idontknow"), gesture + word combinations, and word + jargon strings.

Two-Word Stage ("Telegraphic Speech")

Emerging around 18 months, characterized by relational meanings (Agent + Action, Action + Object, Possessor + Possession) while omitting grammatical morphemes

Sentence Structures & Order of Acquisition:

• Imperatives (Commands) emerge first ("Gimme juice!").

• Declaratives (Statements) and Questions follow.

• Negation: Progresses from external markers ("No wear mittens") to internal placement without auxiliaries ("I no want mittens") to correct auxiliary use ("I don't want mittens")

• Questions: Progress from intonation-only ("Kitty stand up?") to external wh-words ("Where Mommy going?") to full subject-auxiliary inversion ("Where is Mommy going?"). What, where, and who emerge before when, how, and why due to conceptual complexity.

Corrections & Recasts:

Adults correct children implicitly via recasts ("You fell down") and expansions ("The doggie is eating"). Negative input (corrections/recasts) accelerates the mastery of grammatical rules