높임법 (Addressee Honorification)' refers to the way the speaker uses honorifics towards the listener. '상대 높임법 (Addressee Honorification)' is the most developed honorification in Korean Language which is mainly realized by the closing expression, which is then largely divided into formal and informal forms, and categorised into 6 stages according to the degree of honorific. Formal forms include: the '하십시오 체 (hasipsio form)' which is extremely polite form, the '하오 체 (hao form)' which is moderately addressee-raising, the 하게 체 (hage form)' which is moderately addressee-lowering and the '해라 체 (haera form)' which is extremely low form. Informal forms include the '해요 체 (haeyo form)' which is informal addressee-raising and the '해 체 (hae form)' which is informal addressee-lowering. For example, you can write the following sentence differently by using different closing expressions. "Read this book." "이 책을 읽으십시오. (I chaegeul ilgeusipsio.)" : It uses '하십시오 체 (hasipsio form)'. "이 책을 읽으시오. (I chaegeul ilgeusio.)" : It uses '하오 체 (hao form)'. "이 책을 읽게. (I chaegeul ilgge.)" : It uses '하게 체 (hage form)'. "이 책을 읽어라. (I chaegeul ilgeora.)" : It uses '해라 체 (haera form)'. "이 책을 읽어요. (I chaegeul ilgeoyo.)" : It uses '해요 체 (haeyo form)'. "이 책을 읽어. (I chaegeul ilgeo.)" : It uses '해 체 (hae form)'. One must use honorific sentence endings (습니다 and/or 에요/요) in a formal situation or when addressing acquaintances or strangers, regardless of their age or social status (except pre-adolescent children). The following are honorific endings for the four major types of sentences: Declarative: 습니다 Interrogative: 십니까 Prepositive: 습시다 Imperative: 시요, 십시오 However, one does not need to use honorific endings when speaking to close friends or family members, making honorifics optional. In this situation, consider the addressee - some like to be addressed with respect while others prefer friendliness. Declarative: 어/아 Interrogative: 어/아 Prepositive: 어/아 Imperative: 어/아 The setting, ages, occupations, and other factors contribute to the relations between speaker, addressee, and the referent within this system. Traditionally the Korean honorifics were based on hierarchical relation in society, such as rank in occupations, but this has changed over time to develop into a system based on politeness and closeness. Hierarchical based honorific ending are forgone with relationships such as one between older and younger sibling in which the younger sibling uses the “어/아” endings in place of 어요/아요” without change in respect, instead, exhibiting closeness in the