Intonation is a first difference between backward and forward conjunction reduction. Backward conjunction reduction triggers a marked intonation pattern: (8b) shows that the direct object Els, which precedes the elided material in (6b) above, as well as its correlate Peter in the antecedent clause, must be contrastively accented and therefore cannot be replaced by a reduced pronoun. However, example (8a) shows that such a marked intonation pattern is not needed in the case of forward conjunction reduction, as can be seen from the fact that the objects Els and haar in (6a) above can easily be replaced by reduced pronouns. Backward, but not forward, conjunction reduction also requires a distinct intonation break before the coordinator enand, which is indicated by a comma in (8b); note that in later examples we will usually not indicate this break for ease of presentation.

A second difference is that (presumed) forward conjunction reduction generally affects complete clausal constituents (arguments, complementives and adverbials), whereas backward conjunction reduction can also affect parts of clausal constituents. For instance, the two (a)-examples in (9) show that the subject of the second coordinand can be omitted as a whole, but that it is impossible to omit only a part of it: this can be seen from the fact that Oude mannen zijn dom en vrouwen hebben geen gevoel voor humor can only be used to express that women in general (old and young) have no sense of humor. Example (9b), on the other hand, shows that backward conjunction reduction can omit part of a clausal constituent (here: the nominal head of the direct object oude mannen).

Backward conjunction reduction can omit not only parts of phrases, but even parts of words; the only conditions for this are (i) that the omitted part has the same phonetic form as its antecedent, and (ii) that the remnant can be used contrastively. The examples in (10) that illustrate this are taken from Royen (1941). Although Royen objects to this kind of reduction on aesthetic grounds and considers it a borrowing from German, it is often used. We consider the construction to be part of the core syntax because we see no compelling reasons to assume that it should be considered part of the formal register. Note that in writing the omitted part is usually represented by a hyphen, as in schrijf- en spreektaal written and spoken language.

Similar forward conjunction reduction targeting parts of words is hard to find, and constructed examples like those in (11) are unacceptable under the intended reading.

A third difference is that while the target and its antecedent must have the same reference in the case of (presumed) forward conjunction reduction of nominal arguments, this is not true in the case of backward conjunction reduction; cf. Dik (1968:81ff.) and Van Oirsouw (1987:30ff.). The case of forward conjunction reduction in (12a') thus differs from its non-reduced counterpart in (12a) in that the existential quantifier iemandsomeone must refer to one and the same person: the non-reduced form is interpreted to mean that there are two persons, one buying a box of cigars and one buying a bottle of gin, while the reduced form involves a single person buying both a box of cigars and a bottle of gin. The case of backward conjunction reduction in (12b), on the other hand, does not differ in this way from its non-reduced counterpart: both cases are interpreted to mean that the book bought and the book sold refer to different entities.

Subsection II will show that the morphosyntactic and semantic differences between forward and backward conjunction reduction follow naturally if we assume that the former differs from the latter in that it does not result from deletion, but instead involves the coordination of phrases smaller than clauses.

The differences between backward and forward conjunction reduction discussed in Subsection I suggest that the two phenomena cannot be regarded as instantiations of a single reduction process. Neijt (1979:50ff.) claims that all acceptable structures supposedly derived by forward conjunction reduction can also be derived without reduction if we allow the coordination of smaller, non-clausal phrases. For instance, an example such as Mannen zijn dom en gewelddadig does not require forward conjunction reduction, as in (13a), but can be derived without elision by coordinating the two APs, as in (13b). In fact, Neijt claims that representation (13a) is ungrammatical, which we have marked here with an asterisk (although it should be noted that the structure can be derived by gapping, but then the adjectives would usually receive a contrastive accent; cf. Section 39.2, sub I).

Neijt (1979:53) supports the hypothesis that forward conjunction reduction does not exist as a linguistic operation, but should be reanalyzed in terms of regular coordination, by pointing to the acceptability contrast between the examples in (14): the result of applying the forward conjunction reduction operation to the correlative coordinate structure in (14a) is unacceptable, whereas the result of correlative coordination of VPs in (14b) is impeccable. For completeness, note that correlative coordinators can be used to coordinate the reduced clause with its full antecedent clause in the case of backward conjunction reduction: cf. Of Jan heeft Els bezocht of Els heeft Jan bezocht Either Jan has visited Els or Els has visited Jan.

A conclusive argument for allowing the coordination of smaller (i.e. non-clausal) phrases, also based on correlative coordination, is that example (15a) shows that correlative zowel ... als ...both ... and ... cannot be used to coordinate main clauses; cf. Section 38.4.2. This precludes a priori any attempt to derive (14b) or (15b) by conjunction reduction; of course, the acceptability of these examples follows immediately if we assume that we are dealing with the coordination of VPs and APs, respectively.

The rest of this subsection will show that adopting Neijt’s proposal also allows us to derive all the differences between forward and backward conjunction reduction discussed in Subsection I. First, if forward conjunction reduction does not exist, the contrast between the two (a)-examples in (9) on the intended readings follows from the fact that they must be assigned the structures in (16). The attributive adjective oudeold must be combined with the head noun of the subject before the latter can be combined with the verbal predicate; the interpretation of (16a), that old men are not only stupid but also have no sense of humor, thus follows from the fact that the coordinate structure as a whole is predicated of the noun phrase oude mannen. The number sign in (16b) indicates that the intended interpretation of the second clausal coordinand, i.e. that old women have no sense of humor, is impossible without the attributive adjective; this now follows from the proposal that there is no rule of forward conjunction reduction that could elide oude in the second clausal conjunct.

Neijt’s proposal can also be used to explain the unacceptability of the examples in (11): if forward conjunction reduction is really impossible, these forms should be directly derived in morphology. However, on the assumption that the embedded parts of the structures in (17) cannot be formed by morphology, they cannot serve as input to the morphological rule that derives the surface form either. The asterisks again indicate that we are dealing with ungrammatical morphological structures.

This account of the unacceptability of these forms seems perfectly sound for the two (b)-examples, given the standard assumption that affixes must be attached to free morphemes (i.e. that can stand alone as a word). It is also plausible for (17c), given that, at least synchronically, the embedded structure consists of word parts that are not free morphemes: automaatmachine and automobielcar are simplex words in Dutch. However, the compound in (17a) may require some further justification, given the acceptability of the frequently used compound zonsopgang-en-ondergang, to which we will now turn. Example (18a) can be straightforwardly derived by backward conjunction reduction, as expected, but if forward conjunction reduction is excluded in (18b), we must conclude that at least some coordinate structures with free morphemes can be the input for compounding, as in (18b'). That this is indeed possible can be independently motivated by the fact that a morphological process is also needed to derive diminutive and plural forms of coordinate structures of the type kop en schotelcup and saucer: [kop en schotel]-tje and [kop en schotel]-s. Note that the coordinate structure kop and schotel is also special in that the two coordinands must occur in the given order, and that they can occur with a single determiner: cf. de kop en schotel(s).

To account for the contrast in acceptability between huisdeur-en-bel in (17a) and zonsopgang-en-ondergang in (18b'), we can assume that the coordinate structures deur en bel and opgang en ondergang also differ in that the latter, but not the former, can be analyzed as a complex form that can be used as input for further compounding. That opgang en ondergang and the reduced form op- en ondergang can indeed be analyzed as “morphologically” complex forms is supported by two facts: (i) they usually occur in the order given here, and especially (ii) they can easily be preceded by a single determiner. The latter was verified with A Google search (September 9, 2024) for the strings [de opgang en ondergang van] and [de op- en ondergang van], which yielded 85 and 189 hits, respectively. That deur en bel cannot be analyzed as a “morphologically” complex form is supported by the fact that a search for [de deur en bel] did not yield any relevant hits (manually checked).

So far, we have given syntactic evidence for the claim that forward conjunction reduction is not needed to provide a descriptively adequate description of the core data that has been put forward in support of it, and can in fact be better replaced by the independently necessary assumption that coordination of smaller phrases is possible. Below, we provide some additional semantic evidence for the same conclusion, starting with the examples in (19). If (19b) were derived from (19a) by forward conjunction reduction, we would wrongly expect these examples to be synonymous, but this is not the case, as has already been shown in Section 38.1, sub IVC. The two examples differ in that (19b) is true only if at least some boys participated in both the singing and the dancing, whereas this is not necessary for (19a) to be true, since the weaker condition that both activities were performed by at least some boys would be sufficient. If (19b) is derived by coordinating two verbal projections, as in Sommige jongens hebben [[VP gezongen] en [VP gedanst]], this interpretive contrast follows without further ado.

The examples in (20) differ in that (20a) is true only if at least one of the propositions “all men are stupid” and “all men are violent’ is true, whereas (20b) allows both propositions to be false as long as all men are included in the union of the two sets of entities denoted by domstupid and gewelddadigviolent. This interpretive contrast again follows straightforwardly if (20b) is derived by coordinating two adjectival projections, alle mannen zijn [[A dom] of [AP gewelddadig]].

The same reasoning explains the contrast between the two examples in (21), repeated from (12) in Subsection I. If the “reduced” counterpart of (21a) is not derived by conjunction reduction, but by coordination of two noun phrases, as in (21b), the fact that the former is interpreted as relating to two different persons, while (21b) relates to only a single person, follows simply from the difference in the number of clauses, and hence subjects, involved.

The argument can be repeated for referential pronouns such as hijhe in (22); whereas (22a) would normally be interpreted as referring to two separate events involving different agents, (22b) can only be interpreted as a single event involving a particular person buying both a box of cigars and a bottle of gin. This would again be unexpected if (22b) were a reduced version of (22a); cf. De Vries (1992:68ff.) for a more complex version of this argument based on the different uses of hetit (as argument, quasi-argument and anticipatory pronoun).

To conclude, note that although this subsection has argued that the term forward conjunction reduction should be considered a misnomer, we will occasionally use the term as a purely descriptive term in what follows.

This subsection discusses backward conjunction reduction in more detail, and will argue that this form of reduction cannot be given a syntactic account. We have already seen that backward conjunction reduction affects the right periphery of the target coordinand. That omission of material located elsewhere is not allowed is clear from the acceptability contrast between the simple past tense examples in (23b&c) and their perfect tense counterparts in the corresponding primed examples: (23b') is unacceptable and (23c') cannot be interpreted in the intended way (as indicated by the number sign) because backward conjunction reduction is blocked by the clause-final past participle in the first coordinand.

The primeless examples in (23) involve the omission of a single main verb or a single clausal constituent, but the elided sequence can also be larger. For instance, the examples in (24) show that it is also possible to elide more than one clausal constituent: (24a) shows this for two arguments, (24b) for two adverbial phrases, and (24c) for one argument and one adverbial phrase.

The embedded counterpart of (23a) in (25a) further shows that backward conjunction reduction can also affect verb clusters, and the cases in (25b&c) show that it is also possible to elide a clause-final verb (cluster) together with a clausal constituent, a direct object in (25b) and a temporal adverbial in (25c). Note in passing that the complementizer datthat in the second coordinand of (25a) can also be omitted, in which case we may be dealing with the coordination of smaller (non-clausal) verbal projections.

The examples in (24) and (25) are potentially problematic for a syntactic account of backward conjunction, since syntactic operations usually target only one constituent at a time. One might want to defend a syntactic approach by claiming that the omitted constituents in (24) and (25) form a constituent at some higher level, e.g. a verbal projection with the main verb extracted from it by verb-second in (24), or a verbal projection with one or more objects extracted from it by A-scrambling in (25). Such a proposal, however, would run afoul of examples like those in (26). The primeless examples first show that backward conjunction reduction can also target parts of clausal constituents: the elided part is the nominal part of a PP-complement of the verb in (26a) and the nominal part of a postnominal PP-modifier of the object in (26b). The embedded counterparts of these sentences in the primed examples further show that conjunction reduction can also affect the clause-final verb (cluster) plus a phrase embedded in a clausal constituent.

Since the omitted strings in the primed examples of (26) do not count as constituents in any current theory, we cannot adopt the account suggested for (24) and (25) that we are dealing with the deletion of some higher-order verbal constituent. This argument against a syntactic account of backward conjunction reduction gains even more strength from the fact that the elided string may be even more deeply embedded. Besides (26a), in which the elided string is the nominal complement of the preposition, we also have (27a), in which the elided string is the head of that nominal complement. And besides (26b), in which the elided string is the nominal complement of a postnominal modifier of the direct object, we have (27b), in which the elided string is a postnominal modifier of the nominal complement of a postnominal modifier. In short, it seems that the depth of embedding of the elided element knows no principled bounds.

The examples in (28) show that the elided part can be preceded by different kinds of elements; it can be the finite verb, (part of) an argument, a complementive, or (part of) an adverbial phrase.

Note that the part of the target coordinands that precedes the elision site is not a constituent; this seems to rule out the possibility that backward conjunction reduction could be explained by appealing to an independently motivated syntactic operation acting on this part.

The facts discussed in Subsection III suggest that backward conjunction reduction is not a syntactic rule; cf. Neijt (1979: §2.2) and Zwarts (1986:16). Since syntactic rules usually affect only a single clausal constituent, the fact illustrated in (24) that conjunction reduction can affect more than one constituent already raises a red flag. The fact illustrated in (26) that conjunction reduction can affect parts of clausal constituents is also telling, since such parts cannot normally be affected by syntactic rules that apply at the clausal level. The same holds for the examples in (29), where the elided strings are located within syntactic islands: an embedded wh-question in (29a), a relative clause in (29b), and a coordinate structure in (29c), although some speakers seem to object to the last case.

The claim that backward conjunction reduction is not a syntactic rule is consistent with the fact that there can be no established syntactic relations between elements within a coordinate structure if they are in different coordinands. This leads to the conclusion that we are dealing with a post-syntactic phonological rule that deletes a right-peripheral string in the target coordinand under identity with a string in the antecedent clause. Note in passing that the conclusion that backward conjunction reduction is a post-syntactic rule is inevitable in theories that follow Kayne (1994) and especially Chomsky (1995: §4.8) in assuming that information about linear order is not available in syntax, because this makes it impossible to formulate the condition that the elided string is right-peripheral in its clause in syntactic terms.

The conclusion that backward conjunction reduction is a phonological rule that deletes a right-peripheral string in the target coordinand under identity with a string in the antecedent clause is still not descriptively adequate. Recall from Subsection I that the element preceding the elided material, as well as its correlate in the antecedent coordinand, must be contrastively stressed. This means that elements that cannot be stressed cannot precede the gap, as is shown for reduced pronouns in (30a), for the R-pronoun er in (30b), and for the indefinite article eena in (30c); contrastive accents are indicated by small caps. This shows that backward conjunction reduction should also be made sensitive to the prosodic properties of the element preceding the elided string, which of course supports a phonological approach.

A complication is that the marked intonation pattern of backward conjunction reduction is reflected in the fact that it always implies some semantic contrast: in (30a), for instance, two (ordered) pairs <Jan, Marie> and <Els, Peter> are contrasted. Note that the fact that the contrast in this example involves ordered pairs is accidental: in contexts such as (31), it can also involve singletons.

The main conclusion therefore seems to be that backward conjunction reduction requires not only that the elided string is recoverable from the antecedent coordinand, but also that the rightmost part of the remnant and its correlate in the antecedent coordinand can be contrasted both phonetically and semantically. This suggests that backward conjunction reduction cannot be described in purely phonological terms.

The previous subsections have mainly discussed coordinate structures with clausal coordinands. However, example (32) shows that backward conjunction reduction can also apply to coordinands of other categorial types: we have cases of conjunction reduction within nominal, adjectival, and adpositional coordinate structures. We refer the reader to the examples in (10) in Subsection I for examples showing that backward conjunction reduction applies not only within phrases but even within words.

The fact that backward conjunction reduction is possible in non-clausal coordinands is important in light of our earlier conclusion that forward conjunction reduction should be reanalyzed in terms of coordination of phrases smaller than clauses: it makes it possible to account for the fact that backward and forward conjunction reduction can co-occur by assuming that backward conjunction reduction can apply in smaller (non-clausal) verbal coordinands. We illustrate this here with example (6c) from the introduction: the original analysis of this example, repeated as (33a), can now be replaced by the analysis in (33b) with backward conjunction reduction in a coordinated structure of smaller (i.e. non-clausal) verbal projections, which we have labeled VP for convenience.

Combinations of forward and backward conjunction reduction can also be found in nominal coordinate structures, as shown in (34a). Note that the string oude mannen en vrouwen uit Duitsland is ambiguous in several ways and can also be analyzed as in e.g. (34b). The intonation patterns associated with the two cases seem to be different: as always, backward conjunction reduction requires that the element preceding the elided string in the target coordinand as well as its correlate in the antecedent coordinand be contrastively accented, while examples such as (34b) allow a more neutral intonation pattern. Since we are not aware of any systematic investigation of this issue, we leave it to future research.

Similar ambiguities can be found in coordinated APs, as shown in (35): example (35a), with the by now familiar contrastive intonation pattern associated with backward conjunction reduction, expresses that the disappointment and anger are both related to the refusal, while example (35b) has a more neutral intonation pattern and expresses that the disappointment may be related to something other than the refusal (e.g. someone’s lack of commitment as manifested by the refusal).

Similar cases as in (33) to (35) are more difficult to construct for PPs, but it seems that the interpretation of the two sentences in (36) is what we would expect: the contrastive intonation pattern in (36a) triggers a reading according to which each exercise is preceded and followed by the ringing of a bell; under a more neutral intonation pattern, (36b) is compatible with a reading according to which the bell rings at the beginning of a contextually determined event (e.g. a training session) as well as after each exercise.

We conclude with a discussion of the more special case involving R-extraction in (37a). The most likely interpretation of this example is that the degree modifier ergvery has both adjectives in its scope, suggesting the structure given in (37b). If this structure is correct, we must conclude that backward conjunction reduction applies after R-extraction, since only then is the elided preposition in the right periphery of the first coordinand. This finding is of particular theoretical interest because, under the standard assumption that syntactic rules apply cyclically, it supports our earlier conclusion that backward conjunction reduction is a phonological rule that applies after the syntactic derivation has been completed.

Note that the alternative structure in (37b') is predicted to be ungrammatical (which is indicated by an asterisk), because R-extraction would then violate the coordinate structure constraint in Section 38.3, sub II; this prediction seems to be supported by the meaning of (37a), but it is less clear whether it is also supported by intonation, since there are no clear (mandatory) contrastive accents.

The conclusion of Subsection II that forward conjunction reduction does not exist and should now be reanalyzed in terms of the coordination of non-clausal phrases raises several empirical and theoretical problems that still need to be solved, and which in fact play an important role in Wilder’s (1997) plea for the reintroduction of forward conjunction reduction. The central empirical problem is the analysis of examples such as those in (38), in which the initial constituent of the sentence (here a subject) is “shared” by two coordinands.

The theoretical problem is generally considered to be whether coordination is restricted to maximal projections, or whether it is also possible to coordinate (lexical) heads or intermediate projections. Subsection A will show that there are good reasons to claim that coordination of heads is not possible, but Subsection B will show that it is much harder to determine this for intermediate projections. Subsection C sets both these proposals aside and takes a completely different approach to the empirical problem.