Notable exceptions to the prohibition on verb-cluster permeation are bare objects in N + V collocations like paardrijdento ride a horse and pianospelento play the piano in (179).

Examples of this kind need not be a problem for the claim that verb clusters are impermeable if we assume that collocations like paardrijden and pianospelen are compounds when the bare noun permeates a cluster. However, there are several reasons not to follow this proposal. First, bare nouns permeating larger verb clusters need not be adjacent to their associate main verb, as shown in (180). The acceptability of the linear order V1–Noun–V2–Main3 shows that a compound analysis does not fully explain the distribution of bare nouns within verb clusters.

Second, the examples in (181) show that the bare noun cannot be pied-piped when the main verb undergoes verb-second. Examples such as (181) contrast sharply with examples such as Peter stofzuigt graagPeter likes to hoover, where stofzuigento hoover is a compound. A compound analysis of paardrijden and pianospelen requires a separate explanation for the impossibility of pied piping.

Third, participle formation cannot be based on the putative compounds paardrijden and pianospelen, as shown by the fact that the prefix cannot precede the bare noun in (182). Examples such as (182) contrast sharply with examples such as Peter heeft gestofzuigd, where stofzuigento hoover is a compound.

The examples in (180) to (182) show that the compound analysis of paardrijden and pianospelen does not completely solve the problem, and in fact creates a number of new problems. The alternative analysis is that there is in fact no general prohibition against permeation of verb clusters by nominal arguments of the main verb. This is supported by the fact that certain varieties of standard Dutch spoken in Flanders also allow permeation of the verb cluster by bare (singular or plural) objects that do not form a collocation with the verb. In West-Flanders, it is even possible for indefinite and definite objects to permeate the verb cluster, although this should probably be considered a dialectal characteristic.

The examples in (183) have been taken in a slightly adapted form from Barbiers et al. (2008: §2.3.1), where the reader can find more information about the regional distribution of these forms of verb-cluster permeability.

Although adjectival complementives usually precede the verb cluster as a whole, many (but not all) speakers accept permeation of the cluster when the adjective is monosyllabic. In other words, there is a sharp contrast between example (184a) and (184b). Example (184c) further shows that in order to be able to permeate the verb cluster, the adjectival phrase must be simple, in the sense that it cannot be modified by a degree adverb or be otherwise complex.

It has been suggested that the acceptability of the permeation of the verb cluster in examples such as (184a) is due to complex predicate formation, i.e. incorporation of the adjectival complement into the verb, resulting in a compound-like element; cf. Neeleman (1994b). There are several reasons not to follow this proposal. The most important is that bare adjectives that permeate larger verb clusters need not be adjacent to the verb with which they are supposed to form a complex predicate. The acceptability of the linear order V1–Adjective–V2–Main3 in (185a) shows that an incorporation analysis does not fully explain the positioning of bare adjectives within verb clusters. Moreover, on the basis of the incorporation analysis, we would expect the adjective to be pied-piped under verb-second; the fact, illustrated in (185b), that this expectation is not fulfilled thus requires additional stipulations.

Verbal particles, which are also analyzed as complementives in Section 2.2, are even better suited to illustrate that there is no absolute prohibition on the permeation of verb clusters. All speakers of Dutch accept examples such as (186).

It is sometimes suggested that the permeation of the verb clusters in examples such as (186) is due to the fact that we are dealing with compound-like verbs. That this is not obvious is shown by the fact that particles that permeate verb clusters need not be adjacent to their associate verbs (Bennis 1992), and by the fact that they must be stranded when the verb undergoes verb-second in main clauses.

The examples in (188a) further show that many speakers also allow postpositions to permeate verb clusters, and (188b) shows that the same is true for the second part of circumpositions like over ... heenover; cf. van Riemsdijk (1978) and Section P36.2.2 for discussion. However, this is not generally accepted for stranded prepositions like op in (188a), although southern speakers may be more permissive in this respect.

Finally, it can be noted that Barbiers et al. (2008: §2.3.1) shows that West Flemish speakers in particular allow complex PP-complements to permeate verb clusters; again, this may be a dialectal property.

Adverbs are not normally allowed to permeate verb clusters. Since manner adverbs must be construed directly with the main verb, they are best suited to illustrate this fact. An example of an adverb modifying a verb phrase is given in (190b).

The percentage signs again indicate that permeation is not rejected by all speakers; it is acceptable for many speakers from West-Flanders; cf. Barbiers et al. (2008: §2.3.1).

The previous subsections have shown that there is no general ban on the permeation of verb clusters: there is a clear tendency to avoid it, but there are many exceptions, and there is considerable regional variation; more detailed information on regional variation can be found in Sections 5.2.3 and 6.0, as well as Barbiers (2008: §2). There have been attempts to account for some of the cases by assuming that they involve compound verbs or (syntactically created) complex predicates, but we have seen that this still does not fully account for all the facts and sometimes even creates new problems. Furthermore, it is not easy to extend such accounts to account for verb-cluster permeation in some of the more permissive varieties of Dutch such as West Flemish, which also allows (in)definite objects and adverbs to permeate verb clusters. Regardless of whether such varieties should be seen as dialects or as instantiations of a regional variety of standard Dutch, this is quite revealing, since there is reason to believe that the situation in West Flemish corresponds to the older stages of current standard Dutch. The limited amount of permeation that we found in the northern variety of standard Dutch is due to a gradual reduction of the set of elements that could permeate the verb cluster; cf. Hoeksema (1994) and Van der Horst (2008) for more detailed discussion of this diachronic development.