LADEnglishGapping

One of the more challenging phenomena for an implementation in an HPSG grammar is gapping, found in English, Spanish, and other languages. In a sentence such as We gave Kim a book and Lee a laptop there is a notional coordination of two verb phrases, but with the omission of the head of the second VP. In a lexicalist framework, it is difficult to ensure that each of the conjoined headless sequences of complements and modifiers conforms to the subcategorization constraints of the overt head of the first conjunct phrase. It is similarly challenging to provide a compositional semantics of such sentences, where presumably one wants multiple occurrences of the predication introduced by the overt verb, one for each of the notional conjuncts in the gapping construction. The developers of the DELPH-IN grammars for English and Spanish have implemented one analysis of gapping, but at least for English, this analysis has fallen short both in coverage and in efficiency. Hence a better analysis is desired.

Data

VP-level coordination with shared subject

[V NP PP] and _ NP PP

We gave books to Kim and magazines to Chiang.

We visited Tokyo on Monday and Kyoto on Wednesday.

[V NP NP] and _ NP NP

We gave Kim books and Chiang magazines.

We bet Kim a dollar that he would win and Chiang a dollar that he would lose.

We gave books to Kim, magazines to Chiang, and letters to Devito.

Which message did you send to Kim on Tuesday and to Chiang on Friday?

S-level coordination (aka conjunction reduction)

• [NP [V NP]] and [NP _ NP]

  • He admires Paris and she Oslo.

  [NP [V NP PP]] and [NP _ NP PP]

  • She gives books to kids and we magazines to parents.

Corpora

Brown

You've already sent your daughter to Miss X's select academy for girls and your son to Mr. Y's select academy for boys, ...

Once again, he shook his head, kept his face expressionless and his voice very calm, and had a strongly supported alibi ready.

Wall Street Journal (18 items in 22 sections)

When the Germans lost World War I, they lost Namibia to South Africa and the diamonds to Ernest Oppenheimer, patriarch of Anglo American Corp. and De Beers.

"I pay a lot to the farmer and five times the state salary to my employees," he says.

Cast as Violetta Valery in a new production of Verdi's "La Traviata," Ms. Gruberova last week did many things nicely and others not so well.

wsj02/20239030 wsj04/20465039 wsj07/20795009 wsj08/20803007 wsj11/21121014 wsj11/21146132 wsj11/21154003 wsj12/21243004 wsj13/21312027 wsj13/21315016 wsj13/21366008 wsj15/21522001 wsj16/21678003 wsj17/21778087 wsj18/21867016 wsj19/21950027 wsj19/21996006 wsj21/22162011

Conjunction reduction

Whenever the place was cleaned or a meal served it was Precious who did the work.

Time is a queer thing and memory a queerer; the tricks that time plays with memory and memory with time are queerest of all.

Now a little flush came on her pale homely face and enchantment in her eyes.

WSJ (22 items in 22 sections)

The workers can be motivated, and the company reach its full potential, only when management embraces the employees' perspective.

One cell was teased out, and its DNA extracted.

He's not predicting a blockbuster, but he is "more optimistic than three months ago" because employment remains strong and inflation low.

wsj00/20013001 wsj00/20013001 wsj00/20024007 wsj02/20235003 wsj04/20445026 wsj04/20469031 wsj06/20604022 wsj07/20719041 wsj07/20773007 wsj10/21022009 wsj10/21092017 wsj11/21138003 wsj12/21218010 wsj12/21281009 wsj13/21320035 wsj13/21391019 wsj15/21528009 wsj16/21654023 wsj18/21870039 wsj19/21924004 wsj20/22033014 wsj21/22106012

Candidate analysis 1:

Record the VALENCE and the lexical predicate in each verb's HEAD, and use a set of specific four-dtr constructions to admit these sequences:

VP and XP1 XP2

S and XP1 XP2

where the VAL of the left-most dtr constrains the form of the final two dtrs,

and the lex-pred enriches the underspecified EP supplied by the construction for the copied verb's semantics.

Drawbacks of the analysis:

1. Does not extend to three or more conjuncts

2. Uses ad hoc features that preserve lexical information in phrasal projections

3. Impedes efficient processing, since it blocks packing of VPs or Ss with differing internal structure.

Candidate analysis 2:

Always propose a VP whenever you see "and XP YP (ZP) ..."

Actually propose several each time (with gaps for missing complements)

Underspecify the semantic-head predication (e.g. like VP-ellipsis)