This chapter is devoted specifically to the formation and the syntactic behavior of verb clusters. Verb clustering may occur in cases in which a main or a non-main verb takes a non-finite verbal projection as its complement, that is, a phrase headed by a past/passive participle (from now on: participle phrase), a te-infinitive (te-infinitival), or a bare infinitive (bare infinitival). Some issues in this chapter are discussed in greater detail in the course of Section 5.2 and Chapter 6, but since verb clustering is one of the main issues in the scientific discussion of Dutch (and German) syntax, we assume that readers will welcome a more concise discussion that is more specifically focused on this topic.
      Some descriptions of verb clustering take it more or less for granted that any string of verbs in clause-final position can be analyzed as a verb cluster—verb clusters are taken to arise whenever participles, te-infinitives, bare infinitives, and (in embedded clauses) the finite verb occur adjacent in clause-final position. Section 7.1 will show, however, that this is not sufficient and that at least the following two facts should be taken into consideration. First, Section 5.2.2.3 has shown that the grouping of verbs in clause-final position does not only arise as the result of verb clustering in the technical sense of the word, but can also be the result of a process that we referred to as remnant extraposition. Second, Section 6.3.2 has shown that participles and (te-)infinitives sometimes exhibit non-verbal (that is, nominal, adjectival, or adpositional) behavior. The exclusion of such cases simplifies the discussion of verb clustering enormously, and it will enable us to describe the syntactic behavior (more specifically, the linearization) of verb clusters by means of a small number of very simple generalizations.
      After having discussed the ways in which we can recognize verb clusters, we will consider the order of the verbs in such clusters. Two different conceptions of order should be distinguished. Section 7.2 discusses the term hierarchical order, which is basically derived from the selectional properties of the verbs in the cluster: for instance, a perfect auxiliary selects a participial phrase and is therefore superior to (that is, in a structurally higher position than) the participle in the participle phrase: ... Aux [PartP ... Part ...] .... Section 7.3 discusses the term linear order. In this context, it is crucial to note that languages like Dutch differ markedly from languages like English in that the hierarchical order of verbs cannot be read off their linear order. Whereas in English the superior verb must precede the structurally more embedded verbs, verb clustering in languages in Dutch may have the effect of disrupting this one-to-one correlation between hierarchical and linear order. This is illustrated in the (b)-examples in (1), which show that the participle gezien'seen' may occupy various positions in the verb cluster.