Yettili-d usileɣ n uswaɣ s tmerna n yilɣacen isuddimin: s-, ss- ɣer umyag aḥerfi. Ɣef waya i d-yenna Berkai (2009 : 41):  Yettwaleɣ s tmerna (ss-) ma yella tezwar-it-id tiɣri, (s-) ma yella amyag ibeddu s tergalt14.