> In Russian, older bèru (and 2pl. bereté) have adopted the stress of
> the rest of the paradigm (berú, berës^', berëte etc.). Old Russian
> still conserved the old accent pattern.
>
Stang: Slavonic Accentuation
"
b. Recessive stress.
The most clearly established proto-Slavonic example of this type is
the word mogo,, as well as verbs with a semi-vowel in the root-syllable.
Russ. S.-Cr. Slov. Bulg. Czech Slovincian
mogú mògu mó,rem móga mohu mùoga,
moeI m`òe: mó,re móeI mu:e móu,e
(dial. mÓeI etc.)
móet m`òe: mó,re móe mu:e móu,ä
móem m`òe:mo mó,remo móeme mu:^eme móu,emä
móete m`òe:te mó,rete móete mu:z^ete móu,ecä
mógut m`ògu: mó,rejo mógatU mohou mùogou,
The proto-Slavonic paradigm appears fairly easy to reconstruct. We
must assume a conjugation on the following pattern: *mogò,, *mòei,
*mòetI, *mòemU, *mòete, *mògo,tI, *mòeta, *mòete. Agreement
between Russian and Serbo-Croatian on this point is complete and
decisive. In Czech the opposition mohu : mu:e corresponds to the
opposition in Russian mogú: Russ. dial. mÓeI , Serbo-Croatian mògu
: m`òe:.
"
Stang assigns brat' to the same class (e/o-verbs) in "Das slavische
und baltische Verbum". It seems he doesn't agree with you on assigning
original root stress as you do (apart from bereté) to this class.
What is your source for Old Russian bèru?
Torsten