This paper focuses on the morphological distinction between potentially free and obligatorily bound nouns in Harakmbut, an endangered isolate language spoken in the Peruvian Amazon. Bound nouns require a noun prefix to obtain independent nominal status (wa- or e-) and refer to inalienably possessed entities, such as body parts, plant parts, and landscape parts, as well as kinship terms and basic shapes or qualities of entities. The same prefixes, wa- and e-, are also used in verb-based nominalization. The morphosyntactic behaviour of bound nouns is different from that of independent nouns in the areas of noun incorporation, N-N compounds and adnominal modification. However, obligatorily bound kinship terms seem to form exceptions, as they typically pattern similarly to independent nouns in these environments. Special attention will be devoted to adnominal possession, in which the presence versus omission of the noun prefix on the possessee noun makes for subtle semantic differences.