The book is of interest to linguistic researchers and graduate students in linguistics who focus their attention on grammaticalization and subjectification, the functional description of adjectives, questions of deixis and theoretical issues relating to nominal reference. The book is concerned with a hitherto underresearched grammaticalization process: the development from quality-attributing adjective to determiner in the English noun phrase. It takes a bottom-up approach, based on extensive synchronic and diachronic corpus studies of six English adjectives of comparison: other, different, same, identical, similar and comparable. Their functional diversity in current English is proposed to constitute a case of layering, representing the original descriptive use, which expresses how like/unlike each other entities are, and a range of grammaticalized referential uses, which contribute to the identification and/or quantification of the entities denoted by the NP. Diachronic and comparative data material is invoked to verify and further develop the grammaticalization hypothesis.