Spelling Performance of Greek - Speaking Adolescents with Developmental Dyslexia and Developmental Language Disorder

This study investigated spelling performance in Greek-speaking adolescents with Developmental Dyslexia (DD) and those with comorbid Developmental Dyslexia and Developmental Language Disorder (DDLD), compared to typically developing (TD) peers, matched for chronological age (CA) and reading age (RA). A total of 127 participants (29 DD, 16 DDLD, 42 CA, 40 RA) completed measures of fluid reasoning, reading fluency, morphosyntactic skills (production, comprehension), and sentence repetition. A spelling-to-dictation task was also administered, with errors classified into phonological, grammatical, etymological/visual, stress-related, punctuation, and capitalization categories. The DDLD group performed significantly worse overall than CA peers, as well as across all error types, and worse than RA peers in overall, phonological, stress-related, punctuation, and capitalization errors. The DD group performed significantly worse overall than CA peers, making more grammatical and etymological/visual errors. Comparisons between the DD and RA groups did not yield significant differences. Finally, the DDLD group demonstrated significantly poorer performance than the DD group overall and in all error categories except for etymological/visual and punctuation. The above-mentioned results point to more pronounced spelling difficulties in the comorbid group and are discussed in light of the distinct characteristics of the Greek orthographic system.