An Etymological Dictionary of the German Language/beginnen
beginnen, vb. ‘to begin,’ from the equiv. MidHG. beginnen, OHG. beginnan; it corresponds to Goth duginnan, AS. â-, be-, on-ginnan, E. to begin, OLG. biginnan, with a similar meaning. This verbal stem, which appears at an early period only in a compound form, is based upon a pre-Teut. to-, bhi-kenwô, with permutation of k to Teut. g. For the Aryan root ken comp. OBulg. po-čĭną (infin. po-čęti), ‘to begin,’ konĭ, ‘beginning.’