Morphology as an aid in orthographic learning of new words: The influence of inflected and derived forms in spelling acquisition

•We examined whether French children in Grades 3 and 5 benefit from related inflected and derived forms when they learn to spell base nonwords.•In the morphological condition, morphologically related forms provided a cue for the spelling of the final sound of the base-nonword.•In the opaque condition, the base-nonwords were not accompanied by morphologically related forms.•A morphological benefit was observed in both grades for inflectional morphology, but only in Grade 5 for derivational morphology.•These findings suggest that children rely on the root consistency principle earlier for inflectional than for derivational morphology. Prior studies have shown that children are sensitive to the principle of root consistency, whereby root morphemes retain their spelling across related words. The current study used an implicit learning situation to examine, in 56 third grade and 56 fifth grade French-speaking children, whether orthographic learning of new morphologically simple words ending in a silent letter benefited from morphological relatedness with inflected and derived forms. In the morphological condition, the new words (e.g.,clirot with a final silentt) appeared in short stories along with a morphologically related form in which the silent letter of the root was pronounced, justifying the presence of the silent letter in the root word. The morphologically complex form was an inflectional form (e.g.,clirote) for half of the children and was a derived form (e.g.,clirotage) for the other half. In the nonmorphological condition, the new words were not accompanied by morphologically related forms. After children had read the stories, their orthographic learning was assessed by asking the children to choose the correct spelling of each nonword from among three phonologically plausible alternatives (e.g.,clirot,cliros, cliro). Children chose correct spellings more often in the morphological condition than in the nonmorphological condition for both types of morphology in Grade 5 but only for inflectional morphology in Grade 3. Our findings indicate that, in learning new spellings, French children seem to rely on the root consistency principle earlier for inflectional morphology than for derivational morphology. Possible reasons for this developmental delay in mastering derivational morphology are discussed.