An Etymological Dictionary of the German Language/ja

by Friedrich Kluge

ja, adv., ‘yes,’ from the equiv. MidHG. and OHG. jâ (for jă); corresponding to Goth. ja, ‘yes,’ also jai, ‘truly, forsooth,’ OSax. ja, AS. geâ, also gese (for gê-swâ, ‘yes, thus’), whence E. yea and yes. Allied also to Gr. ἢ, ‘forsooth,’ and OHG. jëhan, ‘to acknowledge, confess’ (see Beichte). Lith. ja is derived from G.