Examples
Standard cases of extraposition are optional, although at times the extraposed version of the sentence is strongly preferred. The following pairs of sentences illustrate "normal" word order first followed by the same sentence with extraposition: ::a. Someone whom we don't know left a message. ::b. Someone left a message whom we don't know. - Extraposition of relative clause out of subject ::a. Susan said something that nobody expected more than once. ::b. Susan said something more than once that nobody expected. - Extraposition of relative clause out of object ::a. Some guy with red hair was there. ::b. Some guy was there with red hair. - Extraposition of prepositional phrase out of subject ::a. How frustrated with their kids are they? ::b. How frustrated are they with their kids? - Extraposition of prepositional phrase from predicative adjective phrase ::a. What that was so entertaining actually happened? ::b. What actually happened that was so entertaining? - Extraposition of content clause from subject ''wh''-element ::a. %What that upset everyone do you think they did? ::b. What do you think they did that upset everyone? - Extraposition of content clause from object ''wh''-element These examples illustrate a couple of basic facts about extraposition. One of these facts is that relatively "heavy" constituents are being extraposed (e.g.usually clauses and sometimes prepositional phrases). Another fact is that extraposition can occur out of subjects. This aspect of extraposition is unlikeClause bound
A further widely acknowledged fact about extraposition is that it is clause-bound. This aspect of extraposition is known as the ''Right Roof Constraint''. There is a "right roof" above which extraposition cannot occur. In other words, extraposition cannot occur out of an embedded clause: ::a. That we think that the idea is good is no secret. ::b. *That we think is no secret that the idea is good. - Failed attempt to extrapose out of a subject clause ::a. Someone who thinks that Romney will win was talking non-stop. ::b. *Someone who thinks was talking non-stop that Romney will win. - Failed attempt to extrapose out of a relative clause ::a. Before it was certain that it would rain, we were planning a picnic. ::b. *Before it was certain, we were planning a picnic that it would rain. - Failed attempt to extrapose out of an adjunct clause This aspect of extraposition is unlike fronting discontinuities (topicalization and ''wh''-fronting), which can easily front a constituent out of an (argument) clause, e.g. ::a. They mentioned that they like the coffee. ::b. What did they mention that they like. - Successful ''wh''-fronting out of an object clause but it is like scrambling discontinuities;''It''-extraposition
The term "extraposition" is also used to denote similar structures in which ''it'' appears. While certainly related to canonical cases, ''it''-extraposition is different in at least one important respect. In cases of ''it''-extraposition, extraposition is not optional, but rather it is obligatory, e.g. ::a. *It that I burned the potatoes was frustrating. - Failed sentence because extraposition is obligatory when ''it'' appears ::b. It was frustrating that I burned the potatoes. ::a. *Did it that that happened surprise you? - Failed sentence because extraposition is obligatory when ''it'' appears ::b. Did it surprise you that that happened? ::a. *We suggested it that we leave later than planned to them. - Failed sentence because extraposition is obligatory when ''it'' appears ::b. We suggested it to them that we leave later than planned. ::a. *Nobody believes it that Newt will get the nomination for a second. - Failed sentence because extraposition is obligatory when ''it'' appears ::a. Nobody believes it for a second that Newt will get the nomination. Another aspect of ''it''-extraposition that distinguishes it from canonical cases is that the extraposed constituent is usually a clause; ''it''-extraposition cannot extrapose a prepositional phrase. This fact can be explained by appealing to the status of ''it'' as aMotivation
Extraposition is motivated at least in part by the desire to reduce processing load. When extraposition occurs, it inevitably reduces center embedding and thus increases right- branching. Right-branching structures in English are known to be easier to process. The extent to which extraposition increases right-branching is now illustrated using both a phrase structure analysis and a dependency grammar analysis. The phrase structure trees appear first above the dependency trees: The a-trees, which lack extraposition, extend down, whereas the b-trees, where extraposition is present, grow down and to the right. English, like many other languages, prefers to avoid trees that grow just down. Extraposition is one mechanism that increases rightward growth ( shifting is another).Theoretical analyses
Theories of syntax vary in their analyses of extraposition. Derivational theories are likely to produce an analysis in terms of movement (or copying), and representational theories are likely to assume feature passing (instead of movement). The following trees illustrate these analyses. The movement-type analysis appears on the left in the a-trees, and the feature passing analysis on the right in the b-trees. The phrase structure trees appear again above the dependency trees. On the movement analysis in the a-trees, the embedded clause is first generated in its canonical position. To increase right-branching it then moves rightward (and upward in the case of the phrase structure analysis) to its surface position. On the feature passing analysis in the b-trees, no movement is involved. Instead, information about the extraposed constituent is passed along the path marked in red. This path extends from the extraposed constituent to what can be viewed as theSee also
* Branching * Catena *Notes
References
*Baltin, M. 1981. Strict bounding. In C. L. Baker and J. McCarthy (eds.), The logical problem of language acquisition, 257-295. Cambridge, Massachusetts: MIT Press. *Baltin, M. 1983. Extraposition: Bounding vs. Government-Binding. Linguistic Inquiry, 14, 1, 155-162. *Culicover, P. and M. Rochemont 1990. Extraposition and the complement principle. Linguistic Inquiry 21, 1, 23-47. *Francis, E. 2010. Grammatical weight and relative clause extraposition in English. Cognitive Linguistics 21, 1, 35-74. *Groß, T. and T. Osborne 2009. Toward a practical dependency grammar theory of discontinuities. SKY Journal of Linguistics 22, 43-90. *Guéron, J. 1980. On the syntax and semantics of extraposition. Linguistic Inquiry 11, 637-678. *Guéron, J. and R. May 1984. Extraposition and Logical Form. Linguistic Inquiry 15, 1-31. *Huck, G. and Y. Na 1990. Extraposition and focus. Language 66, 51-77. *Osborne, T. 2012. Edge features, catenae, and dependency-based Minimalism. Linguistic Analysis 34, 3-4, 321-366. *Osborne, T. 2019