Complex sentence: According to R. M. Wilson, of the seventeen sermons one (no.7) is certainly of Middle English origin; two (nos.9 and 10) are adaptations in Middle English of material originally in Old English.
Split into simpler sentences: According to R. M. Wilson, of the seventeen sermons one (no.7) is certainly of Middle English origin. Two (nos.9 and 10) are adaptations in Middle English of material originally in Old English.