Speech-act nouns take the same type of complement as their corresponding verb. This means that finite declarative clauses are always introduced by the complementizer datthat, just like declarative complement clauses of verbs.

The behavior of the interrogative complement clauses of speech-act nouns is also completely on a par with the complements of the corresponding verbs: yes/no questions are introduced by the complementizer ofwhether and wh-questions are introduced by a wh-phrase.

Speech-act nouns denoting a request also take a complement introduced by the complementizer of, although it should be noted that the result is more satisfactory for indirect requests (with vragento ask) than for direct requests (with verzoekento request).

The above examples thus show that all the properties of the complements of the corresponding verbs can be found in these examples. The examples in (629) show that this includes the use of the complex complementizer of (dat) after the wh-phrase found in colloquial speech; cf. V11.3.1.1, sub IV.

If the complement clause is a wh-question, and the content of the proposition is (partially) recoverable from the context, it is often possible to reduce the clause to the constituent containing the wh-element; cf. the discussion of sluicing in Section V5.1.5. Again, this applies to both the input verb and the derived noun.

Speech-act verbs can sometimes appear with a main clause as a direct quote. Again, this property is inherited by speech-act nouns; the examples in (631) show that the felicity of the result depends largely on the property of the input verb.

The results of the discussion so far are summarized in Table 17. All speech-act nouns can take a finite complement in subclause order; as with the corresponding verbs, declarative clauses are introduced by the complementizer datthat, while all other clause types are introduced by ofwhether. The acceptability of a clausal complement in main clause order depends on whether the input verb can take a direct quote as its complement.

For some speakers, the clausal complement of speech-act nouns can be preceded by the preposition vanof (cf. English the question of who ...); cf. V5.1.2.4, sub III. The (a) and (b)-examples in (632), taken from the internet, illustrate this for declarative and interrogative clauses, respectively. Especially examples such as (632b') with an interrogative clause introduced by a wh-word seem to be common.

The occurrence of van may simply reflect the fact that postnominal themes are usually introduced by the functional preposition van. However, there may be more to it than that, since the clausal complement of nouns such as bewering can also be preceded by als, as illustrated again by an example from the internet. To our knowledge, structures like (632) and (633) have not yet been studied, so we leave them for future research.

A proposition noun such as verwachtingexpectation behaves like its input verb verwachtento expect in that it takes a declarative clause introduced by the complementizer datthat.

Sometimes complement clauses follow nouns that are normally used as state-of-affairs nouns, such as ontdekkingdiscovery in (635): (635a') illustrates its normal use, in which it refers to the event of discovering something, while (635b') illustrates its more special use as a proposition noun, in which the complement clause specifies the nature of the discovery. This means that the noun ontdekking is ambiguous, not only in meaning, but also with regard to the type of entity it denotes, just like the corresponding verb ontdekkendiscover; we refer the reader to Section 15.3.1.3, sub I, for a more detailed discussion of ing-nouns.

The type of derived noun determines whether complementation with a clause is possible. This is shown by the fact that the concrete deverbal er-noun ontdekkerdiscoverer in cannot easily take a clausal complement, although it is also derived from the verb ontdekken; although we have found a small number of cases on the internet in which ontdekker takes a clausal complement, the contrast in (636) shows that it prefers to take a theme in the form of a PP (or a genitive noun phrase).

For completeness’ sake, note that some speakers accept the variant of example (636b) with the preposition van introducing the clausal complement, but such constructions probably involve ellipsis of the noun phrase het feitthe fact; cf. de ontdekker van %(het feit) dat de aarde rond is the discoverer of the fact that the earth is round.

There are only a few instances of complement clauses following a non-derived relational noun (see Section 15.2.3). Some examples are given in (637).

For some speakers, the use of van preceding the clause seems to be possible in spoken language: (638a) illustrates this with an example adapted from the internet.

Another special (but common) construction can be found in (639), which is very productive with nouns like geruchtrumor and stellingthesis (as well as with derived speech act nouns like beweringassertion and proposition nouns like verwachtingexpectation). By using this construction, the speaker expresses doubt about the truth or correctness of the claim contained in the complement clause.

The construction is characterized by the remarkable fact that the dependent clause has main clause order: the finite verb occupies the second position of the complement clause. Furthermore, the finite verb is preceded by the element als and must be a past tense form (possibly an old subjunctive) of the modal verb zullenwill.

Adjectives sometimes seem to take a clausal complement, due to the fact that the anticipatory pronominal PP er + P can often be left unpronounced; illustrations of this are given in (640).

It seems that the corresponding deadjectival nouns do not inherit the complement of the input adjective, since the primeless examples in (641) are unacceptable with and without an anticipatory pronominal PP. However, the primed examples show that such constructions are possible (although slightly marked) when the clause follows the preposition. It remains an open question whether we are dealing with ellipsis of a proposition noun phrase like het feitthe fact or with a preposition complemented by a clause, which would imply that inheritance is possible after all; we refer the reader to Section P34.4 for a discussion that may be useful in evaluating the second option.

The (b)-examples in (642) are also potentially relevant to answering this question because they show that interrogative clausal complements cannot be part of the prepositional phrase, although (642b') can perhaps be saved by adding the noun phrase de vraagthe question.

The degraded status of clausal complements with deadjectival nouns follows from the overarching generalization that clauses referring to a proposition can only follow nouns denoting abstract content: in the case of deadjectival nouns, the clause does not specify the content of the head noun, but instead serves to indicate the cause or source of the property or emotion in question.