Language DevelopmentLecture Notes: 10/7/14Copula or auxiliary?● Copula○ To be: verb● Auxiliary○ I amTwo-Word Utterances = Brown’s Stage I● 15-30 months● MLU= 1.74, ranging from 1.0 to 2.0● Two-word stage where children start combining wordsStage II● 28-36 months● MLU = 2.25, ranging from 2.0 to 2.5● Children begin to add grammatical morphemes○ Present progressive○ In○ On○ -s pluralsStage III● 36-42 months● MLU= 2.75, ranging from 2.5 to 3.0● Children begin to use negatives and questions and add use of:○ Irregular past tense○ -s possessive○ Uncontractible copulaStage IV● 40-46 months● MLU = 3.50, ranging from 3.0 to 3.7● Children begin to use complex sentences and add use of○ Articles■ A book, the book○ Regular past tense■ She jumped, he laughed○ Third person regular present tense■ He swims, man brings Stage V● 42-52 months● MLU = 4.00, ranging from 3.7 to 4.5● Third person irregular○ She has, he does● Uncontractible auxiliary○ Are they swimming● Contractible copula○ She’s ready, they’re here● Contractible auxiliary○ They’re coming, he’s goingIn sum● Children’s comprehension of grammar precedes production of grammar● Two-word stage of grammatical development is characterized by preponderance of content words and by telegraphic quality● Development of 14 grammatical morphemes of English is consistent across children, and follows a logical sequence driven by morphemes’ syntactic and conceptual complexityDevelopment of Negatives and Questions● Both involve auxiliary verbs● According to Brown, auxiliaries come last in morphological development● But...children negate and ask questions before they are 3 years old○ Negation = use contracted auxiliaries as unanalyzed units○ Question = use intonation, but not invertedDevelopment of Negatives● First stage: a negative marker is placed outside the sentence (usually in front)● Second stage: a negative word is placed within the sentence, next to the main verb● Third stage: a negative is attached to the auxiliary. Sentences approximate adult constructionsAsking Questions● Yes/No questions vs wh-questions● Yes/No question = formed by reversing the subject of the sentence and the auxiliary. Require a yes or no response● Wh-questions = formed by inverting the subject and the auxiliary, and by placing a wh-word (what, where, which, who, why) at the beginningDevelopment of Wh-Sentences● Stage 1: Auxiliary is omitted● Stage 2: Auxiliary is included, but is not inverted● Stage 3: Auxiliary is included, and is consistently inverted● In general, what, where, and who appear first. When, how, and why appear last● This order of acquisition is probably due to conceptual complexity and to linguistic complexityStructure of Passives● My cat was run over by a bus vs. A bus ran over my cat● Makes the object of the sentence prominent● Passives are also used when speaker does not want to specify the agent of the action atall● Some passives (and actives) are semantically-reversible (i.e., both nouns in a sentence can act as a subject/agent and an object)○ John kissed Mary. ● Some passives (and actives) are semantically irreversible (i.e., only one noun in the sentence can act as an agent)○ John kissed the locket● Passives are very infrequent in children’s productionsDevelopment of Passives● Children understand reversible passives a lot worse than the irreversible ones● Until 5 years of age, reversible passives get interpreted in a linear fashion (the first noun mentioned is interpreted as the subject/agent- the word-order strategy)○ E.g., The cat was bitten by a dog. The cat is the agent● Difficulty with passives may be language-specific○ E.g., in some languages, passives develop very early (around 3 years of