Language is the cornerstone of a culture's world view and values. It is the key to individual and community identity. In the province of Aurora, multiplicity in phonological and lexical disparities among the municipalities exists as evident in some lexical variations among speakers. One of the very peculiar languages in the province is the Kasiguranin language not only because of its unique accent, but also because of the roster of words which could not be deciphered by the people outside the municipality. It is sad to note that the Kasiguranin language is considered "endangered" according to the Ethnic Groups Philippines (2011) because of the limited number of speakers in the community. And when a language is under threat, so is the people's and community's identity. When a language dies, the world, country, people, culture and community loses the unique expressions of culture and world view, and the linguistic uniqueness it represents. The intangible heritage of the society andthe people diminish. Hence, this book is pursued to compile and preserve the Kasiguranin language.