Английский Этимологический словарь - be

BE - O.E. beon, beom, bion "be, exist, come to be, become," from P.Gmc. *beo-, *beu-. Roger Lass ("Old English") describes the verb as "a collection of semantically related paradigm fragments," while Weekley calls it "an accidental conglomeration from the different Old English dial[ect]s." It is the most irregular verb in Mod.E. and the most common. Collective in all Gmc. languages, it has eight different forms in Mod.E.: BE (infinitive, subjunctive, imperative), AM (present 1st person singular), ARE (present 2nd person singular and all plural), IS (present 3rd person singular), WAS (past 1st and 3rd persons singular), WERE (past 2nd person singular, all plural; subjunctive), BEING (progressive & present participle; gerund), BEEN (perfect participle). The modern verb represents the merger of two once-distincts verbs, the "b-root" represented by be and the am/was verb, which was itself a conglomerate. The "b-root" is from PIE base *bheu-, *bhu- "grow, come into being, become," and in addition to Eng. it yielded Ger. present first and second person sing. (bin, bist, from O.H.G. bim "I am," bist "thou art"), L. perf. tenses of esse (fui "I was," etc.),

O.C.S. byti "be," Gk. phu- "become," O.Ir. bi'u "I am," Lith. bu'ti "to be," Rus. byt' "to be," etc. The paradigm in O.E. was: SING. PL. 1st pres. ic eom ic beo we sind(on) we beoр 2nd pres. юu eart юu bist ge sind(on) ge beoр 3rd pres. he is he biр hie sind(on) hie beoр 1st pret. ic wжs we wжron 2nd pret. юu wжre ge waeron 3rd pret. heo wжs hie wжron 1st pret. subj. ic wжre we wжren 2nd pret. subj. юu wжre ge wжren 3rd pret. subj. Egcferр wжre hie wжren The "b-root" had no past tense in O.E., but often served as future tense of am/was. In 13c. it took the place of the infinitive, participle and imperative forms of am/was. Later its plural forms (we beth, ye ben, they be) became standard in M.E. and it made inroads into the singular (I be, thou beest, he beth), but forms of are claimed this turf in the 1500s and replaced be in the plural. For the origin and evolution of the am/was branches of this tangle, see am and was.