in (PGmc ) corresponding to certain adjectives – e.g., "strong", "strength"; "whole/hale", "health"; "foul", "filth". In female forms of several nouns with the suffix (PGmc ) – e.g., "god", "goddess" (cf. German , ); "fox", "vixen". In i-stem abstract nouns derived from verbs (PGmc ) – e.g. "a coming", "to come"; "a son (orig., a being born)", "to bear"; "a falling", "to fall"; "a bond", "to bind". Note that in some cases the abstract noun has a different vowel than the corresponding verb, due to Proto-Indo-European ablaut. Notes The phonologically expected umlaut of is . However, in many cases appears. Most in Old English stem from earlier because of a change called a-restoration. This change was blocked when or followed, leaving , which subsequently mutated to . For example, in the case of "tale" vs. "to tell", the forms at one point in the early history of Old English were and , respectively. A-restoration converted to , but left alone, and it subsequently evolved to by i-mutation. The same process "should" have led to instead of . That is, the early forms were and . A-restoration converted to but left alone , which would normally have evolved by umlaut to . In this case, however, once a-restoration took effect, was modified to by analogy with , and then later umlauted to . A similar process resulted in the umlaut of sometimes appearing as and sometimes (usually, in fact) as . In Old English, generally stems from a-mutation of original . A-mutation of was blocked by a following or , which later triggered umlaut of the to , the reason for alternations between and being common. Umlaut of to occurs only when an original was modified to by analogy before umlaut took place. For example, comes from late Proto-Germanic , from earlier . The plural in Proto-Germanic was , with unaffected by a-mutation due to the following . At some point prior to i-mutation, the form was modified to by analogy with the singular form, which then allowed it to be umlauted to a form that resulted in . A few hundred years after i-umlaut began, another similar change called double umlaut occurred. It was triggered by an or in the third or fourth syllable of a word and mutated all previous vowels but worked only when the vowel directly preceding the or was . This typically appears as in Old