We give an explicit description of the Kac-Peterson-Lepowsky constr tion of the basic representation for the affine Lie algebra sˆo2n(C). Using the conjugacy classes of the Weyl group of sˆo2n(C), we describe all equivalent maximal Heisenberg subalgebras (HSA's) of the correspond: affine Lie algebra. We associate to these HSA's multicomponent charged and neutral free fermionic fields. The boson-fermion correspondence these fields provides us with fermionic vertex operators, whose 'norr, ordered products' give the (twisted) vertex operators of the Kac-Peters( Lepowsky construction.