O.E. beon, beom, bion "be, exist, come to be, become," from P.Gmc. *beo-, *beu-. This "b-root" is from PIE base *bheu-, *bhu- "grow, come into being, become," and in addition to the words in English it yielded German 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. It also is behind Skt. bhavah "becoming," bhavati "becomes, happens," bhumih "earth, world."
The modern verb in its entirety represents the merger of two once-distinct verbs, the "b-root" represented by be and the am/was verb, which was itself a conglomerate. 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 Germanic languages, it has eight different forms in Modern English:
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 paradigm in O.E. was:
SING. PL.
1st pres. ic eom ic beo we sind(on) we beoð
2nd pres. þu eart þu bist ge sind(on) ge beoð
3rd pres. he is he bið hie sind(on) hie beoð
1st pret. ic wæs we wæron
2nd pret. þu wære ge waeron
3rd pret. heo wæs hie wæron
1st pret. subj. ic wære we wæren
2nd pret. subj. þu wære ge wæren
3rd pret. subj. Egcferð wære hie wæren
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.
"That but this blow Might be the be all, and the end all." ["Macbeth" I.vii.5]
词根记忆：
v.
(就)是,等于;(存)在;到达,来到,发生He will be happy in the future.他将来会幸福的.