 The reflexive stem is formed with an infix "-ta", and the derived stems are therefore called Gt, Dt, Št and Nt, and the preterite forms of the Xt-stem are identical to the perfects of the X-stem.Iteratives are formed with the infix "-tan-", giving the Gtn, Dtn, Štn and Ntn.Because of the assimilation of "n", the /n/ is only seen in the present forms, and the Xtn preterite is identical to the Xt durative.