The Relationship Between Lexical and Phonological Development in French-Speaking Children: A Longitudinal Study.

Area of Science:

• Child language acquisition
• Developmental psycholinguistics
• Speech and language pathology

Background:

• Expressive lexicon size is crucial for child language development.
• Understanding factors influencing vocabulary growth aids early intervention.
• Lexical and phonological properties influence word learning.

Purpose of the Study:

• To investigate the influence of lexical and phonological factors on expressive lexicon size in French-speaking children.
• To determine the relative impact of word frequency, phonetic complexity, word length, and neighborhood density on vocabulary size.
• To examine how phonological production skills relate to vocabulary development longitudinally.

Main Methods:

• Longitudinal study of 40 French-speaking children from 22 to 48 months.
• Analysis of lexical properties (phonetic complexity, word length, neighborhood density, word frequency) and phonological production (percent consonants correct, phonetic inventory size).
• Vocabulary size assessed via parent reports; phonological skills extracted from spontaneous speech samples.

Main Results:

• Word frequency of nouns was the most significant predictor of lexicon size across all ages.
• Children acquiring low-frequency nouns demonstrated larger vocabularies.
• Phonological production at 29 months predicted lexicon size at 36 months; word frequency influenced lexicon size at 48 months.

Conclusions:

• Word frequency and phonological production are key factors in expressive vocabulary development.
• Children expand their vocabularies by incorporating increasingly less frequent words.
• Phonological production contributes to vocabulary size up to 36 months of age.