Language Module

In Syntax Reading Group we’ve been reading Negation in Slavic, a collection of papers on the titular subject. Today’s was The Morphosyntax of Polish Verbal Negation: Towards an HPSG Account by Anna Kupść. It’s an interesting paper because it really hammers home the differences between HPSG and the so-called “Standard Theory.”

There’s an attribution - probably apocryphal - of Chomksy saying that HPSG is nothing but a “notational variant” of “mainstream” syntax. It’s tempting to write this off as either trite or condescending. It’s trite in the sense that any syntatic framework should aim to account for the full range of syntactic phenomena; it’s condescending in that it’s uncharitable to think of theories designed by such intelligent people as Pollard and Sag as motivated by nothing other than notational preferences. In either case, it begs the question why anyone would bother to take the time to make up a theory that adds nothing to the discussion? But stop to pause on that and it immediately occurs to you that in fact no one has ever written a full comparison between HPSG and the so-called “Standard Theory.” The apocryphal Chomsky quote may be on point, for all we know!

So whenever I read HPSG papers I’m constantly on the lookout for things that would clue me in to what the fundamental differences are. Are there grounds for preferring one framework over another, and if so, what are they?

For me the “HPSG question” has always broken down like this. The advantages to HPSG are two: it is not (obviously) directional, and it really only possesses a single mechanism for explanation. The first is nice because humans are consumers as well as producers of utterances. The so-called “Standard Theory” is good at production, but not so much at parsing. Working one way, everything is nicely restricted; working the other way, it’s a hopeless data explosion. The second is nice because it keeps researchers honest. One cannot simply invent mechanisms willy-nilly to account for new findings as is possible in the so-called “Standard Theory.” Everything in HPSG must be explained in terms of feature unification.

The advantages of the so-called “Standard Theory” is only one, but it’s hugely important: GB/Minimalism makes transparent generalizations. With HPSG, everything must be explained in terms of local feature unification, even when it’s not obvious how to do that. In particular, this makes word order and long distance dependence problems a bit problematic. There’s no doubt whatever in my mind that HPSG can capture all of the relevant generalizations, it’s just that several of them require rather elaborate feature specifications of the type that sometimes leave one with the impression that it captured the data but missed the point.

Of course, this subject requires a book-length treatment, hardly the sort of thing that can be handled properly in a blog post. I just wanted to say that the Kupść article linked above is a nice illustration of one area where the two frameworks are not mere “notational variants,” and where I think HPSG is better suited to the data.

The problem with Polish negation is that although everyone agrees that negation is a syntactic phenomenon, it behaves in Polish in some ways as though it were an entirely lexical phenomenon.

For example: some Polish verbs are only ever negative, and others seem to have no negative form at all. For some verbs, the negative particle can be separated from the verb by an auxilliary, for others it may not. This sort of “case-by-case” approach to rules is typical of lexical phenomena. Syntactic principles, by contrast, should be universal.

Without really getting into the details, the analysis in the paper takes the approach that some verbs are prespecified for being negative or not in the lexicon. For these verbs, negation is not really a syntactic but a lexical phenomenon. For all the other verbs, negation is syntactic just as it is in all other languages.

The point is that in HPSG, where all syntax is in the lexicon (in the form of lexical features) anyway, you have a good way to “fudge,” as it were, on whether a phenomenon is lexical or syntactic. It works like this. All words (of any category) come with a head feature NEG. For most words this will be unspecified. However, for some it is specified in the underlying lexical entry. Syntactic rules in HPSG operate by taking two (in the typical case- but sometimes it’s more, sometimes less) items that meet their structural description and unifying with those items. In other words, the rule itself acts like a lexical structure that simply fills in its missing blanks with subordinate structures (which can be words, or other such complex structures, actually). Rules can be made to apply to some items but not others by setting features on a “rule” object in such a way that they won’t unify with certain items. In the crudest case, you could simply make a boolean feature “Applies-to-me?” and set it to + or -, and then set the same feature to + on the rule, thereby excluding any items that were pre-specified as -.

So for Polish negation it’s quite simple, actually. Rules can be set up so that they will only unify with items that are not already specified [NEG +]. Those items that are so specified cannot be the arguments to the rule, and thus will behave differently from items that are unspecified for NEG. In a very elegant way, you resolve your “tension” between the language-independent generalization that negation belongs in the Syntax on the one hand and the hard evidence that some Polish verbs form lexical exceptions to this generalization on the other. Since all Syntax is in the lexicon for HPSG, it is easy to write rules that apply to some words and not others - without losing sight of the larger generalization. This is very cool.

I don’t know what the Standard Theory would even do about cases like this. In that theory, for all its pretensions to being a “lexicalist” approach, Syntax and Lexicon are actually quite separate, and it’s hard to write your Syntax in such a way that it applies to some distinguished items of a class in different ways than it does to other members of the same class.

The point of this is not to advocate for HPSG - though certainly I think this case is a plus in the HPSG column. The point is just to note that the two theories are NOT “notational variants,” that though it perhaps looks like that in a lot of cases, they do represent very different approaches to the study of syntactic phenomena grounded in different priorities, and some syntactic phenomena come more naturally to one theory, others to the other.

Of course, as a Computatianal Linguist, I think all such disputes should be resolved on the basis of which comes with the more tractable implementation algorithms!