Impersonal passives are found with verbs that do not take a nominal direct object in the active voice. This set includes (pseudo-)intransitive verbs like lachento laugh, lezento read and voetballen in (57a), intransitive PO-verbs such as spreken (over)to talk about in (57b), and verbs with a direct object clause such as vertellento tell in (57c). Note that passive constructions with a direct object clause allow an indirect object to be present.

The primed examples in (57) show that since impersonal passives lack a subject (i.e. a nominative noun phrase), expletive erthere can be inserted. In main clauses, this is the rule, unless the sentence-initial position is occupied by a topicalized constituent. If the topicalized phrase is an adjunct, as in (58), er is optional.

If the topicalized phrase is an internal argument of the passivized verb, as in (59), the expletive er is often obligatorily omitted. This is especially true if the internal argument is a clause, which may be related to the fact that it acts as the subject of the passive construction.

The difference between constructions with and without the expletive er in the middle field of the clause seems to be related to the presence of a presupposition (“old” information): the presence of er indicates that the sentence does not contain a presupposition, whereas the absence of er indicates that there is a presupposition; cf. Bennis (1986). In (58) and (59) the presuppositions are the topicalized phrases, but topicalization is not a prerequisite for omitting er, as is clear from the fact that er can also be omitted in the embedded clauses in (60), which do not allow topicalization; er is only required if the phrases in question express new information.

That the presence of er in the middle field depends on the presence of a presupposition is particularly clear from the examples in (61). These examples show that the pronominal indirect object mijme blocks the expletive er if it does not occur in the sentence-initial position. This effect is due to the fact that the referents of referential personal pronouns are usually part of the presupposition of the clause. The judgments on the (b)-examples in (61) are supported by the results, given in square brackets, of a Google search (3/24/2024) on the strings [dat er mij verteld werd] and [dat mij verteld werd]. The obligatory presence of the expletive er in (61a) is obviously related to the fact that the sentence-initial position must be filled in declarative clauses.

Regarding (57c), it should be noted that active clauses containing a direct object clause only alternate with an impersonal passive if there is no anticipatory pronoun. In other words, example (62a) only gives rise to the personal passive in (62b), with the anticipatory pronoun het promoted to subject.

Section 3.2.1.1, sub I, claimed that the demotion of the external argument of the verb is the core property of passivization, which is based on the fact that unaccusative verbs cannot be passivized. This subsection discusses a number of special cases in which an unaccusative verb can be found in the impersonal passive.