The Yanesha’ (Amuesha) language is spoken on the edges of two worlds, the Andes and the Amazon, in southcentral Peru. Ethnolinguistic fieldwork was carried out among the Yanesha’ people in May-August 2008 to learn about their language and the possible factors leading to its endangerment. This thesis examines the unique linguistic features of Yanesha and its place within the Arawak language family. It also discusses a puberty ritual that plays an important role in preserving musical and linguistic heritage among Yanesha’ women: the ponapnora female initiation ritual. Keywords: Yanesha’ language, Peruvian Andean Amazon, Arawak language family,