Yurok morphological processes include prefixation, infixtion, inflection, vowel harmony, ablaut, consonantal alternation, and reduplication. This classification is relevant for inflecting the athematic nominals of different accent/ablaut classes. See Athematic accent/ablaut classes of PIE nouns for examples. Many nouns and adjectives are derived from verbal roots via suffixes and ablaut. However, there were some class 7 strong verbs that showed both ablaut and reduplication. Another ablaut alternation is 'horned' from 'horn, roe'. Strong verbs use the Germanic form of conjugation known as "ablaut". They form their past tenses by changing the vowel of the stem (ablaut). Strong verbs ablaut the lemma's nucleus to derive the past forms of the verb. Thematic nominals could also be derived by accent or ablaut changes. Proto-Indo-European verbs, like the nouns, exhibited a system of ablaut. This vowel change is called "ablaut". Both root and suffix ablaut is still well-represented, although again with significant innovations. In Masset Haida and are both very common are involved in spreading and ablaut processes. This process is called "ablaut".