I suspect that most people would find arguments over grammatical terminology to be one of the more soporific topics for discussion. Even if you're interested in learning something about grammar, you probably don't really care about all the variations in terminology. Do we call it a main clause or an independent clause? Who cares? Most of the variations are actually inspired by theoretical concerns. The choice of a particular label can be significant to the extent that the label tells you something about the grammatical theory behind the label. For example, old-fashioned grammar books call a wide range of words (and phrases) "adjectives" when they appear in front of a noun, despite the fact that they have few formal resemblances to ordinary adjectives. In this scheme the, leather, and John's become equivalent to old when they appear before a word like wallet. This choice of terminology makes no distinction between form and function, and it encourages us to believe that these words actually change their parts of speech. More up-to-date grammar books do not lump all these words together into the same category because they distinguish form and function. Sometimes, however, the change in terminology seems so counterproductive that it's hard to see the point. For example, consider the terms determinative and determiner in The Cambridge Grammar of the English Language, a work that I generally hold in the highest regard. The Cambridge Grammar uses determinative as a lexical category for words like articles (the, a/an) and demonstratives (this, that, these, those); determiner refers to a function that is prototypically filled by determiners but which can be filled by other constituents such as genitive noun phrases. So in John's wallet, John's is a determiner, but not a determinative. Now I find the arguments for distinguishing a formal category and a functional role in this instance to be compelling. I'm not complaining about the distinction. The only problem is that older works like A Comprehensive Grammar of the English Language use the terms in exactly the opposite way. There, determiner is the lexical category and determinative is the function. Further, many other works of syntax use determiner as the lexical category. (They don't always distinguish form and function, however.) So why have Huddleston and Pullum switched the terms around? I can find no explanation for the change, either in the Cambridge Grammar or on the web. If you were swap every instance of determinative for determiner in the Cambridge Grammar, and vice-versa, what would be lost, other than the potential of confusion when reading other works?