April 04, 2008

Textbook ambiguities

Many -- indeed, most -- linguistic expressions have more than one meaning.  An apparently trivial observation, but one that leads to all sorts of puzzles in linguistic analysis and theorizing.  The central question is how meanings are associated with linguistic forms, and the answer cannot be that speakers have just memorized all these linkages (though they can have memorized some of them).  Instead, we need to look for some kind of compositional account, in which meanings of smaller expressions and meanings associated with syntactic constructions work together to predict meanings of larger expressions.  One crucial thing such an account has to manage is predicting, both accurately and completely, the range of ambiguities in complex expressions.

There's a huge literature on the subject, including textbook discussions of various ways in which ambiguities can arise.  As it happens, my recent mail has brought me in-the-wild examples of ambiguous sentences of just the sort in textbooks.

From a NYT Magazine piece "Students of Virginity" by Randall Patterson (3/30/08, p. 41):

(1) The Anscombe Society at Princeton went on to embrace positions not just against premarital sex but also against homosexual sex and marriage.

And the head on a piece on the Denver Post website (2/15/08) by T. J. Wihera:

(2) I love my dog more than you

Textbook discussions of ambiguity usually start with really simple cases, in which the ambiguity can be traced back to a word that represents two or more distinct lexical items --

The pen is huge.  [pen 'writing implement', pen 'enclosure for animals', pen 'penitentiary']

or two or more senses of a lexical item --

She is an old friend.  [old 'advanced in age', 'of long standing', 'from former times']

These are "lexical ambiguities" (sometimes called, misleadingly, "semantic ambiguities").  Things then move on to ambiguities in which syntax is crucially involved.  In some examples of "syntactic ambiguity", differences in constituent structure distinguish the different readings; these are sometimes called "phrase structure ambiguities".  The ones that are easiest to find usually involve lexical ambiguities as well as structural differences:

I forgot...  [how good beer tastes]
[how] [ [good beer] [tastes] ]  (with manner how)
[how good] [beer tastes]  (with degree how)

(not to mention the celebrated We saw her duck).  But you can unearth cases where the ambiguity is purely structural.  The classic example is

old men and women
[old] [men and women] 'old men and old women' (a "distributed" reading)
[old men] [and women] 'women and old men' (a "narrow" reading)

made famous in Charles Hockett's A Course in Modern Linguistics (1958:153).  This is what we have in (1), the quote about the Anscombe Society.  Elizabeth Daingerfield Zwicky, who pointed me to the quote, commented:

I was awed at this stand -- even [St.] Paul says it is better to marry than to burn -- before finally realizing that they probably opposed only homosexual marriage.

Elizabeth read "homosexual sex and marriage" at first as having the narrow reading, as did I, but the writer intended the distributed reading.  The narrow reading is favored by the fact that lots of people don't use "homosexual marriage" for this referent: "homosexual marriage" gets 610,000 raw Google webhits; "gay marriage" gets a bit more, 758,000; but "same-sex marriage" (which is the term I use) gets a whopping 5,450,000.  In general, the favoring of one reading of Adj Npl and Npl or the other depends on the adjective and the nouns involved and turns crucially on context, real-world knowledge, and expectations.  "Young children and linguists" will probably get the narrow reading, even out of context (why would we treat young children and young linguists together as a set?), but the classic "old men and women" seems to get the distributed reading almost all the time, to judge from the Google webhits (old men and old women obviously constitute a natural class for many purposes, but putting women and old men into a class would require considerable support from the context).

It turns out that ambiguous Adj Npl and Npl appears in Brians's Common Errors, but in a surprising place, the middle of his entry on Dangling and Misplaced Modifiers.  The general principle is formulated first:

words or phrases which modify some other word or phrase in a sentence should be clearly, firmly joined to them and not dangle off forlornly on their own.

Then, between a discussion of more-or-less classic danglers in which the modifier is separated from the expression it is said to modify and those in which there is no expression at all in the sentence for the modifier to be associated with (and then a discussion of the placement of adverbs like only and even) comes:

Sometimes it's not clear which of two possible words a modifier modifies: "Felicia is allergic to raw apples and almonds." Is she allergic only to raw almonds, or all almonds -- even roasted ones? This could be matter of life and death. Here's a much clearer version: "Felicia is allergic to almonds and raw apples." "Raw" now clearly modifies only "apples."

I'd guess that Brians wanted to discuss this modifier ambiguity, but had no error category to put it in other than Dangling and Misplaced Modifiers, though that's a stretch.

Enough of purely structural ambiguities, and on to ambiguities that appear to be neither lexical nor structural, like (2), I love my dog more than you (which came to me from Victor Steinbok on 2/26/08; Steinbok had earlier sent me a similar example, I will miss you more than anyone else).  The ambiguity here has to do with whether you, the object of than, is understood as parallel to I, the subject of love, or as parallel to my dog, the direct object of love: 'I love my dog more than you love my dog' vs. 'I love my dog more than I love you'.  In this case, the second reading is more plausible than the first, and that turns out to be the intended reading; the piece begins:

I've heard it said that some people like their dogs more than they like most people. I have no doubt that I am one of those people.

In general, the reduced comparative
X Vs Y more than Z
can be understood in either of two ways:
'X Vs Y more than Z Vs Y'
'X Vs Y more than X Vs Z'.
Out of context, and with no real-world considerations to guide you, you can't tell which interpretation is intended, as in textbook-style examples like
Kim likes Terry more than Sandy.
but in context, and with considerations of plausibility taken into account, there is rarely a problem.

Back in the old days, (2) would have been classified as a "transformational ambiguity": an expression with one assignment of words to lexical items and one constituent structure is analyzed as deriving from two different "remote structures" via the application of syntactic "transformations", operations that alter structures in systematic ways.  In the case of (2), the remote structures would be essentially those of the glosses above for (2), and a transformation deletes material in the subordinate than-clauses that duplicates material in the main clause, leaving Z as the (elliptical) remnant.  The semantics of the two readings comes from the remote structures.

There are non-transformational alternatives.  For instance, we could see the problem of analyzing (2) as the problem of finding antecedents for elliptical elements in (2), that is, as a problem of assigning interpretations to anaphoric (in particular, zero-anaphoric) material.  A similar treatment could be offered for the ambiguity in Verb Phrase Ellipsis examples like

You're offering to organize the party?  No one has.
'No one has offered to organize the party'
'No one has organized the party'

There are of course parallel treatments for overt (that is, non-zero) anaphora, as for the personal pronoun she in

Mary's mother thinks she is brilliant.
she refers to Mary's mother
she refers to Mary

Other textbook cases of "transformational ambiguity" share with (2) a central involvement of syntactic functions.  For instance, from John Lyons's Introduction to Theoretical Linguistics (1974), the examples (from various original sources):

the love of God
God understood as the subject of the verb love
God understood as the direct object of the verb love

the shooting of the hunters
the hunters understood as the subject of the verb shoot
the hunters understood as the direct object of the verb shoot

Flying planes can be dangerous.
planes understood as the subject of the verb fly
planes understood as the direct object of the verb fly

These have fairly straightforward non-transformational analyses, in which different constructions pair somewhat similar syntactic forms with different semantics.  Such an analysis is also possible for (2): there would be two comparative ellipsis constructions, one with the remnant NP understood as a subject, the other with the remnant understood as a direct object.  [There is even a prescriptivist tradition, going back to Lowth in 1762, according to MWDEU, which calls for different pronoun cases in the two constructions: Kim likes Terry more than I (nominative) vs. Kim likes Terry more than me (accusative).  But accusative case in both constructions has a long history -- this is usually described as involving a preposition than rather than a conjunction -- and many current speakers and writers simply cannot use a nominative in the first construction; for them, than is just like before and after with NP, as in Kim left  before/after  me/*I 'Kim left before/after I did'.]

Posted by Arnold Zwicky at April 4, 2008 01:29 PM