Some, but not all, speech-act nouns can also be followed by an infinitival complement clause, which is sometimes optionally introduced by the complementizer om. Table 15 gives an indication of the possibilities.

nominal head	complement
declaratives: mededeling ‘announcement’	—
yes-no questions: vraag ‘question’	—
wh-questions: vraag ‘question’	de vraag hoe het probleem op te lossen ‘the question of how to solve the problem’
requests/suggestions/orders: verzoek ‘request’	het verzoek (om) te (mogen) vertrekken ‘the request to be (allowed to) leave’
wishes, ideas, suggestions: advies ‘advice’	het advies (om) te blijven ‘the advice to stay’

The primed examples in (636) show that declarative speech-act nouns do not readily accept infinitival complement clauses. Note that PRO stands for the implied subject of the infinitival clause.

      As far as questions are concerned, it is only wh-questions that can be realized as an infinitival complement clause, which is simply a reflex of the fact that speech act verbs do not take infinitival yes/no questions either. The lack of embedded infinitival yes/no-questions may be due to the fact that there is no linker that can mark infinitival clauses as questions, that is, whereas the complementizer of'whether' can be used to formally mark a finite clause as an embedded yes/no-question, such a specialized marker is lacking for infinitival clauses: the only complementizer-like element is om.

Speech-act verbs like vragen'to ask' do take infinitival wh-questions: Jan vroeg [PRO wat te doen]'Jan asked what to do', which is probably related to the fact that the complement is now explicitly marked as a question by the wh-phrase in clause-initial position. Example (638) shows that the speech-act noun vraag can also take infinitival wh-questions as its complement. Note that the implied subject PRO can either receive an arbitrary interpretation or (optionally) be construed as coreferential with (a referent set containing) the agent of the speech-act noun.

Dependent wh-clauses seem restricted given that wh-phrases with an adverbial function normally give rise to a marked result. A notable exception is hoe'how', which appears very frequently in this construction; we found 432 different instantiations of the string [de vraag hoe te] on the internet. For comparison, we want to mention that we found less then twenty relevant instantiations of the string [de vraag wanneer te], and no relevant instantiations of the string [de vraag waarom te]. The examples in (639a&b) are taken form the internet; (639c) is a constructed example.

The same thing holds for interrogative pronominal PPs of the form waar + P. We searched the internet for the strings [de vraag waar+P te] for the prepositions op, in and over, and for each case we had fewer than 5 hits, which all involved the same verb. The relevant examples are given in (640).

      The facts in (638) to (640) again seem to reflect more or less what we find in the verbal domain, so we may conclude that we are dealing here with inherited arguments. It therefore does not come as a surprise that speech-act nouns derived from verbs denoting the act of asking permission or giving directions readily accept infinitival complements, given that these verbs are typically combined with infinitival clauses. In (642), the implicit subject PRO is interpreted as identical to, respectively, the agent and the goal of the speech-act noun (which may both be left implicit), just as it would be construed as coreferential with, respectively, the agent and the goal of the corresponding verb.

Just as the verb vragen'to ask' can readily be used with the same function as verzoeken'to request' and bevelen'to order', the derived noun vraag'question' can be used with the same function as verzoek and bevel. It differs from these nouns, however, in that it requires explicit mention of the antecedent of the implied subject PRO.

Nouns derived from speech-act verbs like adviseren'to advise' or verzekeren'to assure' also give rise to a fully acceptable result. In (643a) the implicit PRO subject is coreferential with the implied agent of the noun phrase, which in turn is coreferential with the subject of the clause; the complementizer om must be omitted, just like in the corresponding verbal construction. In (643) the implicit PRO subject is coreferential with the goal of the speech-act noun.

As declarative speech-act nouns, proposition nouns denoting statements or facts seem to give rise to a marked result if they take an infinitival complement.

There is a very small set of non-derived nouns that can take an infinitival complement. A typical example is the noun idee'idea' in (645a): the implicit PRO argument can be interpreted arbitrarily or refer to the agent/possessor of the idea. Another potential case is wens'wish' in (645b), provided that one accepts that this noun is non-derived and can be used as input for deriving the verb wensen'to wish' instead of the relation being the other way round.

The fact that the noun feit'fact' in (646) cannot be combined with an infinitival clause shows that not all non-derived nouns that take a finite clause can take an infinitival clause. The difference between (645a&b), on the one hand, and (646b), may be related to factivity: infinitival clauses cannot be factive. This would fit in nicely with the earlier observation that declarative speech-act and proposition nouns cannot take infinitival complements either.

Although some adjectives allow infinitival complements, these complements are not necessarily inherited by the deadjectival noun. Example (647) provides some examples of such clausal complements. As in the case of finite complement clauses (see examples (633) and (635)), the unacceptability of complement clauses with deadjectival nouns can be accounted for by the fact that these nouns do not denote abstract content.

Consider in this respect also the pairs of sentences in (648). As is shown in (648a), the adjective bang'afraid' may take an infinitival complement, preferably introduced by om. However, the deadjectival noun bangheid'fear' in (648a'), though acceptable without a complement, cannot inherit the clausal complement. In the case of the near-synonym angst(ig), on the other hand, the reverse is true. Here, the denominal adjective angstig'afraid' in (648b) cannot take a clausal complement. The basic noun angst'fear' in (648b'), however, is a (relational) proposition noun that does accept an infinitival complement clause. Finally, there are cases like the (c)-examples in (648), in which both the adjective and the derived noun accept an infinitival complement.