fatemeh forooghan geransayeh

The present sturdy studies the semantic function negative prefixes »na « and »bi « in Persian. The founder of this approach using six semantic features, studies semantic function of morphological items, including affixes and their function in the processes of compounding, derivation and conversion. In the present research, data which is collected from the second version of" Hamshahri" corpus and polysemy of prefixes »na «and »bi «has been studied according to the type and meaning of stem. analyzing data suggests that different meanings of prefix » na «are due to co- indexing principle. This principle, can't explain the negative meaning in some cases and for the elaboration of negative meaning in these cases we need to put away the principle and pay attention to semantic features of stem; although this issue is not correct about prefix »bi «and we can explain all negative meanings conveyed by this affix. Also, it was shown that negative prefixes  »bi « and  »na « are adjective maker; except, in some small amount of cases.