themyoudaoicibaDictYouDict[them 词源字典]
them: [12] The Old English set of forms of the third person plural pronoun was hīe, hiera, and him. These were replaced at the end of the Old English period by they, their, and them, which came from Old Norse, but the colloquial ’em for them is a lineal descendant of him.
=> their, they[them etymology, them origin, 英语词源]
them (pron.)youdaoicibaDictYouDict
third person plural pronoun, c. 1200, from Old Norse þeim, dative of plural personal and demonstrative pronoun þeir (see they). Replaced Old English cognate him, heom.