Purpose of the present study

is something we might well say to a visitor from abroad, and not think twice about whether holiday and today or the -ing of celebrating and of fascinating function differently from the point of view of our knowledge of language. However, linguists, grammarians, and others who study and think about language, how it is structured, how we come to know it, and how it changes concern themselves with just such questions. In the introduction to the Concise Oxford Dictionary of Linguistics, Matthews says: “Everyone will agree that linguistics is concerned with the lexical and grammatical categories of individual languages” (1997:vi), and this is what our example in (1) is about: holiday, celebrate, and fascinating are usually regarded as “lexical,” members of large, “open” classes of forms that are relatively infrequently used and express relatively concrete meaning, while we, are, and a are regarded as “grammatical,” members of smaller, relatively “closed” classes of forms that are very frequently used and express relatively abstract meaning. Moreover, today is not clearly a lexical or a grammatical form, having partially concrete and partially abstract meaning, and belonging to a rather large set of adverbs. Finally, the -ing of celebrating and the -ing of fascinating, although seen as originating in the same grammatical form, are generally understood as having developed differently over time, the former remaining grammatical and the latter becoming lexical.