sluicing (grammar)

Glossary of Grammatical and Rhetorical Terms

In his paper "Guess Who?" (1969), John R. Ross offered this example of sluicing: "Somebody just left. Guess who?". (Christopher Furlong/Getty Images)


In English grammar, sluicing is a type of ellipsis in which a wh- word or phrase is understood as a complete statement.

"What is characteristic for sluicing," notes Kerstin Schwabe, "is that the wh-clause—we call it sluicing clause (SC)—contains merely a wh-phrase. The antecedent sentence . . . introduces the discourse referent the wh-phrase is related to" (The Interfaces: Deriving and Interpreting Omitted Structures, 2003).


The concept of sluicing was first identified by linguist John Robert Ross in his paper "Guess Who?" (CLS, 1969), reprinted in Sluicing: Cross-Linguistic Perspectives, ed. by J. Merchant and A. Simpson (2012).

See Examples and Observations below. Also see:


Examples and Observations

  • "I want him to respect and admire me for something, but I don't know what."
    (Patricia Cornwell, Isle of Dogs. G.P. Putnam's Sons, 2001)

  • “Uncle Henry told me to expect someone, but he didn't say who."
    (William Kent Krueger, Northwest Angle. Simon & Schuster, 2011)

  • "My folks were fightin' last week, but I don't know what about."
    (Earl Greenwood and Kathleen Tracy, The Boy Who Would Be King. Dutton, 1990)

  • Indirect Licensing
    "[T]he mechanism of indirect licensing is illustrated with the sluicing example in . . . (5):
    (5) Someone was singing La Marseillaise, but I don't know who.
    The sluiced clause in (5) is to be interpreted as an embedded question '(I don't know) who was singing La Marseillaise,' but this question itself is not uttered."
    (Lobke Aelbrecht, The Syntactic Licensing of Ellipsis. John Benjamins, 2010)

  • Movement of the wh- Phrase
    "Sluicing refers to examples like those in (30), which is ellipsis of the sentential complement to an interrogative complementizer hosting a wh-phrase:
    (30a) Jack bought something, but I don't know what.
    (30b) A: Someone called. B: Really? Who?
    (30c) Beth was there, but you'll never guess who else.
    (30d) Jack called, but I don't know {when/how/why/where from}.
    (30e) Sally's out hunting—guess what!
    (30f) A car is parked on the lawn—find out whose.
    Ross's take on the sluicing was to assume that the wh-phrase has been moved from its usual position to the beginning of the clause. That movement operation is then followed by phonetic deletion of the rest of the clause (including the position from which wh-movement originated)."
    (Cedric Boeckx, Linguistic Minimalism: Origins, Concepts, Methods, and Aims. Oxford University Press, 2006)

  • Stranded wh- Phrases
    "The story begins with [John RobertRoss (1967), who offers a strategy for the resolution of sluicing—a stranded wh-phrase illustrated in (1)-(3).
    (1) I was afraid of something that day, but I didn't know of what.

    (2) A: You want a massage?
    B: By who?

    (3) Psst. Wanna copy contracts over to yahoo!? Here's how.
    Following the conventions in the (linguistic) literature, I will henceforth refer to a stranded wh-phrase as a sluice and the preceding material that supports its interpretation as an antecedent.

    "Ross shows that clear syntactic effects cluster around sluicing, pointing to a pre-deletion structure beyond what is visible. . . .

    "To this, Merchant (2004, 2006, 2007) adds another observation. Prepositions can apparently be omitted under sluicing only if preposition stranding produced by wh-movement is a feature of the language--e.g., English but not German.
    (7) Peter was talking with someone, but I don't know (with) who.
    Who was he talking with?"
    (Joanna Nykiel, "Whatever Happened to English Sluicing?" Studies in the History of the English Language V: Variation and Change in English Grammar and Lexicon: Contemporary Approaches, ed. by Robert A. Cloutier, Anne Marie Hamilton-Brehm, and William A. Kretzschmar, Jr. Walter de Gruyter, 2010)


    Pronunciation: SLEW-sing