Eskimo–Aleut languages
Every word must have only one root (free morpheme) always at the beginning. Eskimo–Aleut languages have a relatively small number of roots: in the case of Central Alaskan Yup'ik, around two thousand. Following the root are a number of "postbases", which are bound morphemes that add to the basic meaning of the root. If the meaning of the postbase is to be expressed alone, a special neutral root (in the case of Central Alaskan Yup'ik and Inuktitut "pi") is used.