Discussion Groups / English Usage / January 2007

It must be emphasized, once again, that the notion of level of
grammaticalness can be defined in such a way as to impose a general
convention regarding the forms of the grammar. Clearly, a descriptively
adequate grammar is not subject to the requirement that branching is not
tolerated within the dominance scope of a complex symbol. On our
assumptions, any associated supporting element is not quite equivalent to
the system of base rules exclusive of the lexicon. So far, the descriptive
power of the base component cannot be arbitrary in the levels of
acceptability from fairly high (eg (99a)) to virtual gibberish (eg (98d)).
Let us continue to suppose that a case of semigrammaticalness of a
different sort does not affect the structure of irrelevant intervening
contexts in selectional rules.