This paper discusses the theoretical and practical concerns in part-of-speech (POS) tagging for Chinese. Unlike other languages such as English, Chinese lacks morphological marking in association with categorial alternations. We consider such categorial fluidity a continuum, and any categorial shift a transition, with special focus on the verb-noun shift. Preliminary observations are reported on this phenomenon from empirical data, and we suggest that POS tagging should not only be theoretically valid but also sufficiently capture the extent of categorial fluidity as reflected by the data. .
