I read the older work of Rodney Huddleston (co-writer of CGEL) in which he implemented structural linguistics in defining the word categories in a language: he said "The fundamental principle of what we are calling the structural approach to linguistic analysis is that the units and categories postulated for the grammar of a given language are determined by the syntagmatic and paradigmatic relations that obtain within the sentences of that language (Introduction to the Grammar of English, page 50).
So I'd like to know how structuralism linguistics plays an important role in defining word categories in the book CGEL? From what I understand, one can look at the relationship between forms in a sentence (syntagmatic relationship) and one can also compare one form to another (paradigmatic relationship), so that they come up with grammatical properties of a word category: for example,
By comparing the construction a. and b., one can conclude that the subject has these grammatical properties:
- Its default position is before the verb.
- In interrogative clauses, it typically occupies a distinctive position just after the verb.
Is this the example of how paradigmatic relationships help defines a word category, or do I just understand the whole concept wrong?