Raiders of the lost archetype: eo in the strong verbs of classes IV and V

The standard handbooks for Old English, based on West Saxon, show -e- vocalism in the infinitive and present plural of the strong verbs of classes IV and V: e.g. beran/berabear, sprecan/sprecaspeak. This is surprising, since e with a back vowel in the following syllable 'should' undergo back umlaut, resulting in beoran, beora, etc. 'Correct' -eo- vocalism in the relevant parts of the present system of class IV and V strong verbs is in fact attested in West Mercian Old English (e.g. Vespasian Psalter). Such spellings also appear in some early Middle English Southwest Midland spelling systems, including 'AB language'. In this paper we examine the forms recorded for the relevant categories of class IV and V strong verbs in the LAEME corpus of tagged texts to evaluate the possible survival of an 'archetypal' tradition of eo vs e use.