language acquisition: lecture 3 lexical and semantic development
TRANSCRIPT
Lexical and Semantic Development …
• Lexical development = a child’s acquisition of words.
• Semantic development = a child’s acquisition of the meanings associated with those words.
Be careful …
• REMEMBER: vocabulary acquisition does not end at a certain age. We continue hearing and learning new words and their meanings throughout our lives.
Rate of acquisition …
• End of first year: child begins to speak.
• 18 months: vocabulary of about 50 words.
• 2 years: vocabulary of about 200 words.
EXPLOSION!!!
• 5 years: vocabulary of 2000 words.
• 7 years: vocabulary of 4000 words.
Understanding …
• The previous figures refer to word use.
• At each stage, the number of words understood by the child is expected to be higher.
• 18 months: 250 words understood.
Meanings …
• When a child adds a new word to their vocabulary, they are not immediately aware of its full range of meanings.
• More time is required to acquire this additional knowledge.
First words …
• Research has shown that there are predictable patterns in the words and word classes first acquired by children.
First words …
• Predictably, a large proportion of a child’s first words refer to familiar people, objects and aspects of social interaction.
Word classes …
• Nouns• Verbs• Adjectives
• Concrete nouns• 5-7 years: abstract
nouns begin to be used.
Word classes …
• Grammatical function words: noticeably absent in the early stages of lexical acquisition.
Under-extension …
• Common semantic error made by children.
• A word is given a narrower (under extended) meaning.
• ‘cat’ is the family pet, but not other cats.
Over-extension …
• Another common semantic error. Opposite of under-extension.
• A word is given a broader (more general, over extended) meaning.
Overextension …
• ‘daddy’ for all men, rather than just the child’s father.
• ‘dog’ for all four-legged animals.
Over-extension …
• More common: than under-extension.
• 50 word vocabulary: one third are likely to be overextended.
Getting it right …
• Age 2 ½ : marked decrease in number of overextensions.
• Explanation: child’s vocabulary is increasing rapidly, thus filling the gaps previously filled by overextended words.
Understanding …
• REMEMBER: children’s understanding of word meanings is ahead of their ability to produce the corresponding words.
Aitchison (1987) …
• Three stages/processes occur during acquisition of vocabulary:
Labelling Linking words to the objects to which they
refer Understanding that objects can be labelled
Packaging Exploring what labels can apply to. Over/under
extension occurs in order to understand the range of a word’s meaning
Network building
Making connections between words – understanding similarities and opposites in meanings