[Extract:] The notion ?word? is versatile. It spans a number of interrelated concepts. A ?phonological word? as a minimally pronounceable unit is recognized strictly on phonological criteria. Establishing its boundaries requires an in-depth knowledge of the sounds system and phonological processes in a language. A ?grammatical word? is recognized on morphological and syntactic principles. In order to fully identify it, a linguist will need to have a good grasp of the internal workings of the language, covering every aspect of its grammar. Criteria for recognizing a phonological word include: (a) Segmental features–internal syllabic and segmental structure and their phonetic realization depending on their position; word boundary phenomena (such as final devoicing of voiced stops), and pause phenomena, including interruptability: speakers usually pause between words but not within one word. (b) Prosodic features–stress (or accent) and/or tone assignment; further suprasegmental features such as nasalization, retroflexion, aspiration, vowel harmony, and harmony of other kinds (including nasal harmony, illustrated for Chamacoco in Chapter 4 of this volume). (c) Phonological rules applying within a phonological word (e.g. internal sandhi rules), or across word boundaries (external sandhi rules).