he

The word 'he' — the masculine third-person singular pronoun — descends from Old English 'he' (he, that one), from Proto-Germanic *hiz, from the PIE demonstrative stem *ḱe-/*ḱi- (this, here).‌​‍​‌​‍​‌​‍​‍​‌​‌​‍​‌​‌​‍​‌​‌​‌​‌​‍​‍​‌​‌​‍​‍​‍​‍​‍​‍​‌​‍​‌​‍​‍ It is cognate with 'it' (from the neuter form of the same demonstrative), 'here' (at this place), 'hence' (from this place), and 'hither' (to this place).

The critical insight about 'he' is that it was not originally a word meaning 'male person.' It was a demonstrative pronoun — a pointing word meaning 'this one' — that was assigned to the masculine gender class in Proto-Germanic. The gender system was originally grammatical, not biological: nouns were classified as masculine, feminine, or neuter based largely on phonological patterns, and the pronouns 'he/she/it' tracked these grammatical classes. Only later, as English lost its grammatical gender system during the Middle English period, did 'he' become specifically a pronoun for male beings.

The Old English third-person pronoun paradigm was: 'he' (he, nominative masculine), 'heo' or 'hio' (she, nominative feminine), 'hit' (it, nominative neuter). The masculine and feminine forms were dangerously similar in some dialects — 'he' and 'heo' could sound almost identical in rapid speech. This phonological collision may have contributed to the eventual replacement of 'heo' by 'she' (a form of disputed origin, possibly from the demonstrative 'seo').

The oblique forms of 'he' — 'him' (dative/accusative) and 'his' (genitive) — come from the same Proto-Germanic paradigm. 'Him' is from Proto-Germanic *himmai (to this one, dative), and 'his' from *hes (of this one, genitive). The use of 'his' as a neuter possessive ('the tree shed his leaves') persisted through the Early Modern period and is found throughout the King James Bible and Shakespeare, before being displaced by the new form 'its.'

The broader demonstrative family from *ḱe-/*ḱi- includes 'here' (Old English 'her' — at this place), 'hence' (from this place, away from here), 'hither' (to this place), and the archaic 'hie' (to go quickly — originally 'to go to this place, to hasten here'). All of these 'h-' words are deictic — they point to locations relative to the speaker, just as 'he' points to a previously identified person.

The absence of a clear PIE ancestry for 'he' as a personal pronoun is itself significant. PIE did not have third-person personal pronouns in the way Modern English does. The third person was expressed through demonstratives — 'this one,' 'that one' — and each branch of the family independently recycled different demonstrative roots into personal pronouns. This is why third-person pronouns vary wildly across Indo-European languages while first and second person ('I/me,' 'you') are relatively consistent.