In linguistics, ellipsis (from , élleipsis 'omission') or an elliptical construction is the omission from a clause of one or more words that are nevertheless understood in the context of the remaining elements. There are numerous distinct types of ellipsis acknowledged in theoretical syntax. Theoretical accounts of ellipsis seek to explain its syntactic and semantic factors, the means by which the elided elements are recovered, and the status of the elided elements. Theoretical accounts of ellipsis can vary greatly depending in part upon whether a constituency-based or a dependency-based theory of syntactic structure is pursued.
Background
Varieties of ellipsis have long formed a basis of linguistic theory that addresses basic questions of form–meaning correspondence: in particular, how the usual mechanisms of grasping a meaning from a form may be bypassed or supplanted via elliptical structures. In generative linguistics, the term ellipsis has been applied to a range of syntax in which a perceived interpretation is fuller than that which would be expected based solely on the presence of linguistic forms.
One trait that many types and instances of ellipsis have in common is that the appearance of ellipsis is optional. The occurrence of VP-ellipsis, for instance, is often optional, e.g. He will help, and she will (help), too. Whether or not the second occurrence of the verb help is elided in this sentence is up to the speaker and to communicative aspects of the situational context in which the sentence is uttered. This optionality is a clear indication of ellipsis. At other times, however, ellipsis seems to be obligatory, for instance with cases of comparative deletion, e.g., *More girls were there today than girls were there yesterday. The second occurrence of girls must be omitted in this sentence (More girls were there today than were there yesterday). The obligatory occurrence of ellipsis complicates the analysis, since one can argue that obligatory cases are not really instances of ellipsis at all, but rather a null pro-form is involved. These aspects of the theory should be kept in mind when considering the various types and instances of ellipsis enumerated below.
Types
There are numerous widely acknowledged types of ellipsis. They include, as mentioned and briefly illustrated below: Gapping Stripping Verb phrase ellipsis Pseudogapping Answer ellipsis Sluicing Nominal ellipsis Comparative deletion Null complement anaphora Among experts, there is no unanimity that all of the abovementioned syntaxes form a natural class in the sense of being derived by one and the same mechanism. Ellipsis-based accounts have been given for other syntaxes, and some of the above have been analyzed in other ways. Most experts would agree, however, that most of the above items are in fact ellipses, so the discussion below takes their status as ellipses largely for granted.
The example sentences below employ the convention whereby the elided material is indicated with subscripts and smaller font size. All examples given below come from English though similar patterns arise cross-linguistically, with variation from language to language.
Gapping
Gapping occurs in coordinate structures. Redundant material that is present in the immediately preceding clause can be "gapped". This gapped material usually contains a finite verb. Canonical cases have a true "gap" insofar as a remnant appears to the left and to the right of the elided material.
John can play the guitar, and Mary can play the violin. Fred took a picture of you, and Susan took a picture of me.
While canonical cases have medial gaps as in these two sentences, the gap need not be medial, and it can even be discontinuous, e.g.:
She persuaded him to do the homework, and he persuaded her to do the homework. Should I call you, or should you call me?
While these two sentences again each have two remnants, the gapped material is no longer continuous. There are in a sense two gaps in each of the gapped clauses. Gapping has been thoroughly studied, and it is therefore reasonably well understood, although the theoretical analyses can vary significantly.
Stripping
Stripping is also known as bare argument ellipsis. Many linguists take stripping to be a particular manifestation of gapping whereby just one remnant appears in the gapped clause instead of the two (or more) that occur in instances of gapping. The fact that stripping is limited to occurring in coordinate structures is the main reason why stripping is integrated into the analysis of gapping:
John can play the guitar, and Mary can play the guitar, also. Sam has attempted problem 1 twice, and he has attempted problem 2 too.