The main factors that are relevant to language change are: (1) Sound assimilation refers to the physiological effect of one sound on another. (2) Rule simplification and regularization are a type of spontaneous morphological rule change that involves exceptional plural forms of nouns. (3) Internal borrowing is led by the need to lessen the burden on memory. (4) Elaboration occurs when there is a need to reduce ambiguity and increase communicative clarity or expressiveness. (5) Sociological triggers: Radical socio-political changes such as wars, invasions, occupation, colonialization, and language planning and standardization policies lead to vigorous language changes. (6) Cultural transmission: The continual process of cultural transmission seems to be one of the most pervasive sources of language change.