An analysis of 's and of possessives in EFL textbooks and authentic supplementary materials used in a reading and writing course at Bungnaloowittaya school in Kantharalak, Srisaket province

This study aims at investigating the use of 's and of possessives that show possession in EFL and authentic narrative materials to discover if there might be similarities or differences between the two text types and how the possessive rules are described in EFL and English grammar books. The 8 narrative texts were chosen for the study. There were 4 narrative texts from EFL textbooks and the rest was
taken from authentic supplementary materials that contained the 's and of possessives. In addition, the rules described in the grammar books of EFL and native English
speaking contexts were taken into consideration. The results indicated that the of form was used more frequently than the 's possessive for showing possession in both EFL and authentic text types. Most of the of form in both texts
tended to be found with inanimate head nouns whereas the 's was likely to be used with the same type of head nouns. In addition, it was evident that both similarities and differences on the possessive rules were witnessed in the
grammar books of the two contexts. Finally, the results also suggested that the functions of possession found in all sample texts were description, relationship/ association and part/whole. However, the description function was evidently used more than the two.