The researcher , in the current study , studies one of the human categorization theories which is known as ‘ prototype theory’ . He sets a questionnaire to fourth class students at Kirkuk university by using the prototype theory . A good number of every days’ expressions is used as data . The students are required to choose one of the tabulated expressions and give the reason of choosing that expression as well . The reasons ( factors) are the taxonomy of the used model . Two analysis methods namely qualitative and quantitative are followed to arrive at the desired results . The aims of the study are ( 1) showing what can influence the typical member . (2) Showing how people are distinct in creating the prototype. Its hypotheses are (1) each individual has his / her own prototype . (2) The social factors like ( age , religion , one’s background knowledge , etc …) have roles in the formation of the prototype . The study is concluded with points like the context has a well-built relation with the process of creating the prototypical category member .