Relationships Between Morphological Knowledge, Spelling and Writing in Adolescents

Background Spelling proficiency is crucial for expressing abstract ideas in writing. In secondary school, students are increasingly required to spell morphologically complex, subject‐specific words, but such words are challenging to spell, and few studies have investigated how morphological knowledge contributes to spelling and writing performance in secondary students. Methods Two hundred and sixty‐six Year 7 students (M = 13 years, 1 month; SD = 4 months) from seven Australian schools completed a task of curriculum‐relevant morphologically complex spelling, as well as tasks of morphological knowledge, standardised spelling, vocabulary, reading fluency and cognitive ability. Writing quality was indexed by National Assessment Program–Literacy and Numeracy (NAPLAN) scores. Correlational and regression analyses examined relationships between morphological knowledge, spelling and writing. Results Morphological knowledge explained 26% of the variance in spelling, though its unique effect declined after controlling for vocabulary and reading. Moderate correlations were found between the morphological knowledge task and all spelling measures ( r = 0.43–0.48), indicating broad relevance across formats. Spelling was also strongly associated with writing scores ( r = 0.57–0.63), underscoring the role of transcription in writing. Conclusions Findings highlight the importance of morphological knowledge in adolescent literacy and support the integration of morphology‐focused instruction and assessment in secondary classrooms. Implications for task design, assessment validity and future research in curriculum‐aligned literacy practices are discussed.