Edward Sapir (18841939). Language: An Introduction to the Study of Speech. 1921.
most languages would present such irregularities of morphological contour as to lose touch with their formal ground-plan. Sound changes work mechanically. Hence they are likely to affect a whole morphological group herethis does not matter, only part of a morphological group thereand this may be disturbing. Thus, the old Anglo-Saxon paradigm:
fet (older foti)
could not long stand unmodified. The oe alternation was welcome in so far as it roughly distinguished the singular from the plural. The dative singular fet, however, though justified historically, was soon felt to be an intrusive feature. The analogy of simpler and more numerously represented paradigms created the form fote (compare, e.g., fisc fish, dative singular fisce). Fet as a dative becomes obsolete. The singular now had o throughout. But this very fact made the genitive and dative o-forms of the plural seem out of place. The nominative and accusative fet was naturally far more frequently in use than were the corresponding form of the genitive and dative. These, in the end, could not but follow the analogy of fet. At the very beginning of the Middle English period, therefore, we find that the old paradigm has yielded to a more regular one:
The starred forms are the old nucleus around which the new paradigm is built. The unstarred forms are not