hisyoudaoicibaDictYouDict[his 词源字典]
his: [OE] His originated as the standard genitive form of the masculine personal pronoun he, with the genitive ending -s – what in modern English would be expressed as of him. But comparatively early in the Old English period it began to replace the ancestral third person possessive adjective sīn (a relative of modern German sein ‘his’), and by the year 1000 it was also being used as a possessive pronoun, as in ‘It’s his’.
=> he[his etymology, his origin, 英语词源]
his (pron.)youdaoicibaDictYouDict
Old English his (genitive of he), from Proto-Germanic *hisa (cognates: Gothic is, German es). Originally also the neuter possessive pronoun, but replaced in that sense c. 1600 by its. In Middle English, hisis was tried for the absolute pronoun (compare her/hers), but it failed to stick. For dialectal his'n, see her.