An Etymological Dictionary of the German Language/gehen
gehen, vb., ‘to go, walk, go on well, succeed,’ from the equiv. MidHG. and OHG. gên, gân (some of the inflected forms supplied by the stem gang; see Gang); comp. AS. gân (stem gâ-, from gai), E. to go, OSwed. and ODan. ga, ‘to go.’ The assumed root ghai-, meaning ‘to go,’ cannot be positively authenticated beyond the Teut. group (yet comp. Lett. gâju, ‘I went’?). The remarkable facts that this Teut. gai, ‘to go,’ has no primit. noun derivatives in Teut., that it has supplanted the root i, which is widely diffused in Aryan, but almost obsolete in Teut. (retained, however, in the Goth. aorist iddja, AS. eóde), and that like the latter it is conjugated like verbs in mi — all these lead to the supposition that the assumed Goth. *guim, *gais, *gaiþ are contracted from the verbal particle ga (see ge-) and the old inherited îmi, îsi, îti (comp. Gr. εἶμι, Sans. êmi, êši, êti), ‘to go.’ From this explanation it follows that gehen is fundamentally identical with Lat. îre, Gr. ἰέναι, Sans. root i, Lith. eíti. OSlov. iti, ‘to go’ (see eilen). For a similar blending of a verbal particle and an old vb. comp. folgen, fressen.