Icelandic Primer with Grammar, Notes and Glossary

by Henry Sweet

Vowels

21. The vowels are related to one another in different ways, the most important of which are mutation (umlaut), fracture (brechung), and gradation (ablaut).

Mutation

22. The following changes are i-mutations (caused by an older i or j following, which has generally been dropped)³:

[Footnote 3: Many of the i's which appear in derivative and inflectional syllables are late weakenings of a and other vowels, as in bani (death) = Old English bana; these do not cause mutation.]

a (ǫ) ... ę :-- mann (man acc.), męnn (men); hǫnd (hand), hęndr (hands).

ā ... æ :-- māl (speech), mæla (speak).

e (ja, jǫ) ... i :-- verðr (worth), virða (estimate).

u (o) ... y :-- fullr (full), fylla (to fill); lopt (air), lypta (lift).

ū ... ȳ :-- brūn (eyebrow), pl. brȳnn.