Pied-piping

In linguistics, pied-piping is a phenomenon of syntax whereby a given focused expression takes an entire encompassing phrase with it when it is "moved". The term itself is due to John Robert Ross; it is a reference to the Pied Piper of Hamelin, the figure of fairy tales who lured rats (and children) by playing his flute. Pied-piping is an aspect of discontinuities in syntax, having to do with the constituents that can and cannot be discontinuous. While pied-piping is most visible in cases of wh-fronting of information questions and relative clauses, it is not limited to wh-fronting, but rather it can be construed as occurring with most any type of discontinuity (extraposition, scrambling, topicalization). Most if not all languages that allow discontinuities employ pied-piping to some extent, although there are major differences across languages in this area, some languages employing pied-piping much more than others.

Typical examples of pied-piping occur when a wh-expression drags with it an entire encompassing phrase to the front of the clause. The focused expression is in bold in the following examples and the fronted word/phrase in the b- and c-sentences is underlined. The material that has been pied-piped is therefore any underlined material that is not bolded. The gap marks the canonical position of the fronted expression:

In each of the b-sentences, the interrogative word has pied-piped an encompassing phrase with it, whereas each c-sentence is bad because pied-piping has not occurred. These examples illustrate that the pied-piped phrase can be a noun phrase, an adjective phrase, or an adverb phrase, and examples further below illustrate that it can also be a prepositional phrase. Pied-piping occurs in embedded wh-clauses as well:

And pied-piping is very frequent in relative clauses, where a greater flexibility about what can or must be pied-piped is discernible:

The pied-piping mechanism is more flexible in relative clauses in English than in interrogative clauses, because it can pied-pipe material that would be less acceptable in the corresponding interrogative clause, e.g.

The d-examples, where pied-piping has occurred in a relative clause, are acceptable, whereas the corresponding wh-clauses in the b- and c-sentences are much less acceptable. This aspect of pied-piping - i.e. that it is more restricted in wh-clauses than in relative clauses in English - is poorly understood, especially in light of the fact that the same contrast in acceptability does not obtain in closely related languages such as German.

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