This chapter discusses the two main types of (putative) ellipsis found in coordinate structures: conjunction reduction and gapping. Conjunction reduction involves the elision of material in one coordinand, the target, on the basis of identical material in another coordinand, the antecedent. The tradition following Ross (1967) distinguishes two different forms: forward conjunction reduction (FCR) refers to cases where the antecedent coordinand precedes the target coordinand, as in (1a), and backward conjunction reduction (BCR) refers to cases where the antecedent follows the target, as in (1b). The hypothesized omissions are indicated by a strikethrough.

However, Neijt (1979) has argued that backward conjunction reduction is the only genuine form of conjunction reduction; supposed cases of forward conjunction reduction, such as (1a), should be reanalyzed as cases in which phrases smaller than clauses are coordinated, as in (2). Decisive reasons for adopting this alternative analysis will be given in Section 39.1, where the two forms of (supposed) conjunction reduction will be discussed in more detail. Until then, for the sake of presentation, we will represent forward conjunction reduction as in (1a) rather than as in (2).

The two putative types of conjunction reduction always involve the omission of material in the periphery of the target coordinand; forward conjunction reduction elides material in the left periphery, while backward conjunction reduction elides material in the right periphery. This distinguishes conjunction reduction from gapping, which is illustrated in (3). The properties of this form of reduction, which minimally targets the finite verb and applies only in a forward fashion, will be discussed in Section 39.2.

Although the examples in (4) show that conjunction reduction and gapping do not only occur in coordinate structures with conjunctive enand, but can also be used in coordinate structures with disjunctive ofor and adversative maarbut, we will generally use the conjunction en in our examples.

Section 39.3 will show that backward conjunction reduction and gapping can occur together in a single sentence; this is illustrated in (5), where simple strikethrough indicates material elided by gapping, and bold strikethrough indicates material elided by backward conjunction reduction.

The discussion of gapping in Section 39.2 follows the standard assumption that gapping occurs only in coordinate structures. However, there are reasons to believe that it can sometimes occur in subordinate clauses. Section 39.4 examines such cases in detail and concludes that the standard assumption should be abandoned.

Many of the Dutch examples presented in Sections 39.1 through 39.3, as well as the conclusions drawn from them, are inspired by Neijt (1979); we acknowledge this here to avoid continuous reference to the same source. For a discussion of ellipsis in contexts other than coordinate structures, we refer the reader to Sections V5.1.5 (fragment clauses) and A27.4 (N-ellipsis).