Verb phrase ellipsis

In linguistics, 'Verb phrase ellipsis' (VP ellipsis or VPE) is a type of grammatical omission where a verb phrase is left out (elided) but its meaning can still be inferred from context. For example, "She will sell sea shells, and he will _{<sell sea shells>} too" is understood as "She will sell sea shells, and he will sell sea shells too" (tree structure illustrated to the right). VP ellipsis is well-studied, particularly in English, where auxiliary verbs (e.g., will, can, do) play a crucial role in recovering the omitted verb phrase. The reliance on auxiliary verbs gives English a distinctive mechanism for VP ellipsis, making it one of the most researched languages in this area. VP ellipsis can occur partially (e.g. argument ellipsis) or as a whole verb phrase. For instance, Japanese employs a phenomenon known as verb-stranding VP ellipsis, where the verb remains while the rest of the phrase is elided. This cross-linguistic perspective reveals that VP ellipsis is not unique to English, but varies in its structural realization across languages.

With English grammar, VP ellipsis must be introduced by an auxiliary verb (be, can, do, don't, could, have, may, might, shall, should, will, won't, would, etc.) or by the infinitive particle to. Under VPE, the finite auxiliary and modal verbs cannot be elided. In the examples below, the elided material of VP ellipsis is indicated using subscripts, strikethrough represents that the material has been moved, the antecedent to the ellipsis is bolded, and asterisk (*) signals an ungrammatical sentence:

Attempts at VP ellipsis that lack an auxiliary verb fail, unless the infinitive particle to is retained:

A particularly frequent construction in which VP ellipsis (obligatorily) occurs is in tag questions:

Apparent exceptions to the restriction that VP ellipsis can only occur in the context of an auxiliary verb or infinitive particle are analyzed as instances of null complement anaphora:

VP ellipsis can be said to operate either forwards or backwards: it operates forwards when the antecedent to the ellipsis precedes the ellipsis (as in the above examples) and backwards when the antecedent follows the ellipsis. It can also be said to operate either upwards or downwards (or neither). It operates upwards when the antecedent appears in a clause that is subordinate to the clause containing the ellipsis, and downwards when the ellipsis appears in a clause subordinate to the clause containing the antecedent. In the above examples, the two clauses are coordinated, so neither is subordinate to the other, and hence the operation of the ellipsis is neither upward nor downward.

Combinations of these directions of operation of ellipsis are illustrated with the following examples. In these examples, the subordinate clause who say they will help is a relative clause that modifies the noun people. This relative clause is extraposed out of the subject in examples (11a) and (11b) in order to illustrate the remaining combinations:

Three of the four combinations are acceptable. However, as the fourth example shows, VP ellipsis is impossible when it operates both backwards and upwards.