Of Pre-Greek origin according to Frisk, possibly from Egyptian *kai "other" (in writing ky, becoming ke in Sahidic), developing a sense of "also" by Late Egyptian. A link with Proto-Indo-European conjunctive particle *kʷe "and" (whence Latin -que) is unlikely for phonetic reasons.
- (5th BC Attic): IPA: /kă͜ɪ̆́/
- (1st BC Egyptian): IPA: /kɛ/
- (4th AD Koine): IPA: /ke/
- (10th AD Byzantine): IPA: /ce/
- (15th AD Constantinopolitan): IPA: /ce/
καί • (kaí)
- και (kai, “and”)