be (v.)youdaoicibaDictYouDict[be 词源字典]
Old English beon, beom, bion "be, exist, come to be, become, happen," from Proto-Germanic *biju- "I am, I will be." This "b-root" is from PIE root *bheue- "to be, exist, grow, come into being," and in addition to the words in English it yielded German present first and second person singular (bin, bist, from Old High German bim "I am," bist "thou art"), Latin perfective tenses of esse (fui "I was," etc.), Old Church Slavonic byti "be," Greek phu- "become," Old Irish bi'u "I am," Lithuanian bu'ti "to be," Russian byt' "to be," etc. It also is behind Sanskrit bhavah "becoming," bhavati "becomes, happens," bhumih "earth, world."

The modern verb to be 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 Modern English 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 Old English 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 wæswe wæron
2nd pret.þu wærege waeron
3rd pret.heo wæshie wæron
1st pret. subj.ic wærewe wæren
2nd pret. subj.þu wærege wæren
3rd pret. subj.Egcferð wærehie wæren


The "b-root" had no past tense in Old English, 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 Middle English 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]
[be etymology, be origin, 英语词源]
did (v.)youdaoicibaDictYouDict
Old English dyde, past tense of do (v.). The only remainder in Germanic of the old linguistic pattern of forming a past tense by reduplication of the stem of the present tense. Far back in Germanic the equivalent of did was used as a suffix to make the past tenses of other verbs, hence the English -ed suffix (Old English -de).
feign (v.)youdaoicibaDictYouDict
A 17c. respelling of fain, fein, from Middle English feinen, feynen "disguise or conceal (deceit, falsehood, one's real meaning); dissemble, make false pretenses, lie; pretend to be" (c. 1300), from Old French feindre "hesitate, falter; be indolent; lack courage; show weakness," also transitive, "to shape, fashion; depict, represent; feign, pretend; imitate" (12c.), from Latin fingere "to touch, handle; devise; fabricate, alter, change" (see fiction).

From late 14c. as "simulate (an action, an emotion, etc.)." Related: Feigned; feigning. The older spelling is that of faint, feint, but this word acquired a -g- in imitation of the French present participle stem feign- and the Latin verb.
go (v.)youdaoicibaDictYouDict
Old English gan "to advance, walk; depart, go away; happen, take place; conquer; observe, practice, exercise," from West Germanic *gaian (cognates: Old Saxon, Old Frisian gan, Middle Dutch gaen, Dutch gaan, Old High German gan, German gehen), from PIE *ghe- "to release, let go" (cognates: Sanskrit jihite "goes away," Greek kikhano "I reach, meet with"), but there does not seem to be general agreement on a list of cognates.

A defective verb throughout its recorded history; the Old English past tense was eode, a word of uncertain origin but evidently once a different verb (perhaps connected to Gothic iddja); it was replaced 1400s by went, past tense of wenden "to direct one's way" (see wend). In northern England and Scotland, however, eode tended to be replaced by gaed, a construction based on go. In modern English, only be and go take their past tenses from entirely different verbs.

The word in its various forms and combinations takes up 45 columns of close print in the OED. Meaning "cease to exist" is from c. 1200; that of "to appear" (with reference to dress, appearance, etc.) is from late 14c.; that of "to be sold" is from early 15c. Meaning "to be known" (with by) is from 1590s; that of "pass into another condition or state" is from 1580s. From c. 1600 as "to wager," hence also "to stand treat," and to go (someone) better in wagering (1864). Meaning "say" emerged 1960s in teen slang. Colloquial meaning "urinate or defecate" attested by 1926, euphemistic (compare Old English gong "a privy," literally "a going"). To go back on "prove faithless to" is from 1859; to go under in the figurative sense "to fail" is from 1849. To go places "be successful" is by 1934.
went (v.)youdaoicibaDictYouDict
past tense of go; originally the strong past tense and past participle of wend (v.). The original past tense forms of wend were wende, wended, but variants wente, went developed from c. 1200 and these then began to replace older past tenses of go. By c. 1500 they were fully employed in that function, and wend was given a new past tense form, wended.