Origin and history of personally

late 14c., "private, pertaining to the self or to a self-conscious individual; performed by the individual himself," from Old French personal (12c., Modern French personnel), from Late Latin personalis "pertaining to a person," from Latin persona (see person).

The meaning "applicable to, directed at, or aimed at some particular person" (usually in a hostile manner) is attested from 1610s. Designating an official or employee attached to one's person (as in personal secretary) by 1928.

The noun sense of "newspaper item about private matters" is attested from 1888. As "a classified ad addressed to an individual," it is recorded from 1861. Personal computer is from 1976.

common adverbial suffix, forming, from adjectives, adverbs signifying "in a manner denoted by" the adjective; Middle English -li, from Old English -lice, from Proto-Germanic *-liko- (source also of Old Frisian -like, Old Saxon -liko, Dutch -lijk, Old High German -licho, German -lich, Old Norse -liga, Gothic -leiko). See -ly (1). It is cognate with lich, and identical with like (adj.).

Weekley notes as "curious" that Germanic uses a word essentially meaning "body" for the adverbial formation, while Romanic uses one meaning "mind" (as in French constamment from Latin constanti mente). The modern English form emerged in late Middle English, probably from influence of Old Norse -liga.