Irregulars in _en_.
The Irregulars of the Third Class form the Past Time by changing the
vowel or diphthong of the Present; and the Participle Perfect and Passive
by adding the termination _en_, beside, for the most part, the change of
the vowel or diphthong. These also derive their formation in both parts
from the Saxon.
Present. Past. Participle.
_a_ changed into _e_.
Fall, fell, fallen.
_a_ into _o_.