Vocabulary sophistication in children's L2 school writing

This paper tests three hypotheses about written vocabulary in child L2 English. Specifically, as children mature, (1) the mean frequency values of the nouns they use increase; (2) the mean frequencies of other parts-of-speech decrease; (3) the use of academic vocabulary increases only in certain types of writing. Using a corpus of writing by children in Norway, hypothesis 1 was confirmed up to the mid-teenage years. The mean frequency values of nouns then decreased. Analysis showed that the early increase is due to decreased repetition of low-frequency topic words. After age 15, frequencies drop as the main source of vocabulary moves from a region around the 150th most frequent lemma to one around the 550th. Hypotheses 2 and 3 were partially confirmed. Mean frequencies of non-nouns decreased in non-stories after Year 9. Non-stories became more academic across school years. Stories had much lower scores overall but also showed an increase at Year 10.