Inessential Features and Expressive Power of Descriptive Metalanguages

Linguists employ a variety of features, ranging from traditional, such as morphosyntactic features like those encoding person or number, to more recent inventions encoding bar level and gap locations. Linguists feel intuitively that there is a distinction between (i) real features reflecting genuine properties of languages and (ii) formal tricks exploiting the feature machinery. Our thesis in this chapter is that this issue is trickier and more subtle than might be thought. Notions like ‘spurious feature distinction’ or ‘artifact of the descriptive machinery' are not really well-defined. There is a very close relationship between expressiveness of the formal metalanguage and necessity of particular features: in a fairly precise sense captured by a theorem, the more expressive the descriptive metalanguage employed, the smaller the number of features that need to be posited.