In syntax, sluicing is a type of ellipsis that occurs in both direct and indirect interrogative clauses. The ellipsis is introduced by a wh-expression, whereby in most cases, everything except the wh-expression is elided from the clause. Sluicing has been studied in detail in recent years and is therefore a relatively well understood type of ellipsis. Sluicing occurs in most languages.
Sluicing is illustrated with the following examples. The "sluiced" material is indicated via subscripts and a smaller font and the antecedent to the sluiced material is shown in bold:
- Phoebe wants to eat something, but she doesn't know what she wants to eat.
- Jon doesn't like the lentils, but he doesn't know why he doesn't like the lentils.
- Someone has eaten the soup. Unfortunately, I don't know who has eaten the soup.
Sluicing in these examples occurs in indirect questions. It is also frequent in direct questions across speakers, e.g.
- Somebody is coming for dinner tonight. - Who is coming for dinner tonight?
- They put something in the mailbox. - What did they put in the mailbox?
The examples of sluicing above have the sluiced material following its antecedent. This material can also precede its "antecedent", e.g.
- Although I don't know why the pictures have been moved, the pictures have been moved.
- When and how somebody should say something is unclear, but somebody should say something.
In some languages, sluicing can leave behind more than one wh-phrase (multiple remnant sluicing). Multiple sluicing in English is rare, but it is marginally possible in constructions like the following ones:
- Someone wants to eat something. ?I wish I knew who wants to eat what.
- ?Something is causing someone big problems, although it's not clear what is causing who big problems.
Sentences like these are considered grammatical in languages like German, Japanese, Turkish, Russian, and others, although in English, their acceptability seems marginal. Multiple sluicing raises a potential problem for syntax, since the elided content appears to form a non-constituent.
Ross (1969), who was the first to examine sluicing, assumed that sluicing involves regular wh-fronting followed by deletion of the sister constituent of the wh-phrase. This analysis has been expanded in greater detail in Merchant 2001, which is the most comprehensive treatise on sluicing and ellipsis. The fronting plus deletion analysis is challenged by instances of multiple sluicing, however, since it is not clear how both wh-expressions could be fronted (or otherwise moved) in such a manner that would allow the remaining constituent to then be deleted.
An alternative analysis of sluicing, and of multiple sluicing in particular, takes the catena (as opposed to the constituent of phrase structure grammars) as the fundamental unit of syntax. The catena is a unit of syntactic analysis that is closely associated with dependency grammars; it is defined as any word or any combination of words that is continuous with respect to dominance. The elided material of all instances of sluicing, even of multiple sluicing, are catenae. The following dependency trees of the two examples of multiple sluicing from above illustrate the point:
The antecedent to the sluiced material is in bold, and in the sluiced material itself is indicated with a lighter font. Both the antecedent and the sluiced material qualify as catenae. The same is true of the second example:
The antecedent to the sluiced material and the sluiced material itself again qualify as catenae (but not as constituents).
- See for instance Ross 1969, Chung 1994, and Merchant 2001.
- See Osborne et al. (2012).
- Chung, Sandra, William Ladusaw, and James McCloskey. 1995. Sluicing and Logical Form. Natural Language Semantics.
- Ross, John 1969. Guess who? CLS.
- Merchant, J. 2001. The syntax of silence: Sluicing, identity, and the theory of ellipsis. Oxford University Press.
- Osborne, T., M. Putnam, and T. Groß 2013. Catenae: Introducing a novel unit of syntactic analysis. Syntax 15, 4, 354-396.