This section on finite prepositional object (PO-)clauses is relatively short given that many of their properties and of the anticipatory pronominal PPs introducing them have been discussed in Section 2.3. PO-clauses never have the form of main clauses and come in two types: declarative clauses introduced by the complementizer dat'that' or interrogative clauses introduced by the complementizer of'whether' or some wh-phrase. Some examples are given in (240). The question as to whether a declarative or an interrogative clause will be used depends on the verb: a verb like klagen (over)'to complain (about)' in (240a) selects a declarative clause, whereas the verb twijfelen (over) in the (b)-examples selects an interrogative clause.

The examples in (240) show that clause-final PO-clauses can be introduced by an anticipatory pronominal PP in the middle field of the clause. Depending on the verb in question, this PP can be optional or obligatory. The former holds for the verbs in (240) and the latter for the verbs in (241). An extensive sample of PO-verbs that can or cannot drop the anticipatory pronominal PP can be found in Section 2.3.1, sub VI.

PO-clauses can be left-dislocated, in which case the anticipatory pronoun is replaced by a resumptive pronominal PP in the form of daar + P. This is illustrated in (242) for the examples in (240); the (discontinuous) resumptive PP is in italics.

Although some speakers seem to allow omission of the pronominal part of the resumptive PP, most people reject this. This is indicated in (243), in which pro stands for the empty/deleted resumptive pronominal part, by means of a percentage sign.

Note in passing that the fact that most speakers do not accept examples such as (243) may be a potential problem for Koster's proposal discussed in Section 5.1.2.2, sub III and Section 5.1.3, sub II, the substance of which was that apparent sentence-initial object and subject clauses are actually left-dislocated and that the first position of the sentence is in fact filled by an empty pronominal element pro. If the resumptive pronoun can be phonetically empty in the case of subject and object clauses, why is this excluded for most speakers in the case of PO-clauses? Note also that the examples in (243) do not improve if the prepositional part of the resumptive pronominal PP is left out. Although some speakers may perhaps marginally accept examples such as (244), they contrast sharply with the examples without an anticipatory PP in (240), which are fully grammatical.

PO-clauses cannot be placed in the middle field of the clause, irrespective of whether or not an anticipatory PP is present. PO-clauses normally do not occur as part of the PP-complement of the verb either; examples such as (245) are quite marked compared to examples such as (240), which is indicated here by means of a question mark (although Section P2.4.1, sub I, discusses a number of exceptional circumstances that do seem to license PPs of the type in (245)).

We want to conclude by noticing that there are als-clauses that can easily be erroneously analyzed as PO-clauses; We refer the reader to Paardekooper (1986:1.18.9, B2) for a concrete case of such a misanalysis, but we will use example (246a) for reasons of representation. The two examples in (246a) differ, however, in that the als-clause but not the dat-clause can be followed by dan'then' if the als-clause occurs on the first position of the utterance, suggesting that we are dealing with a conditional adverbial clause. This suggestion is supported by the fact that there is a sharp difference between the two variants of example (246c), in which the clauses appear as part of the PP-complement: whereas the dat-clause gives rise to a marked but interpretable result, the als-clause gives rise to an unacceptable and uninterpretable result.

A final argument for assuming that the als-clause is a conditional adverbial clause is that it can occupy the sentence-initial position while the anticipatory pronominal PP erover is present; if the als-clause were a PO-clause, we would end up with two prepositional objects within a single clause. Analyzing the als-clause as a conditional adverbial phrase, on the other hand, is unproblematical given that we may then give (247a) a similar analysis as (247b).

For more discussion of the incorrect analysis of conditional als-clauses as argument clauses we refer the reader to Section 5.1.2.1, sub VI, to Section 5.1.3, sub I, for similar cases in the domain of object and subject clauses.