In this paper we present criteria for an n-quasigroup to be isotopic to an n-group. We call a such n-quasigroup G−n-quasigroup. Applications to functional equations on quasigroups are presented in a subsequent paper. 2000 Mathematics Subject Classification: 20N15. Some important n-quasigroup classes are the following. An n-quasigroup (A,α) of the form α(x1 ) = n ∑ i=1 fi(xi)+a, where (A,+) is a...