'Of' and 'off' are the same word split in two — and their Latin cousin 'ab' gave us 'absent' and 'abstract.'
Expressing the relationship between a part and a whole; indicating possession, origin, or association.
From Old English "of" (away from, out of, from), from Proto-Germanic *af (off, away from), from PIE *h₂epo- (off, away). The PIE root *h₂epo- is the source of Latin "ab" (from, away), Greek "apó" (from, away from), and Sanskrit "ápa" (away). In Old English, "of" and "off" were the same word with both stressed and unstressed variants; the spelling