The impersonal passive is found with verbs that do not take a nominal direct object in the active voice. This set includes (pseudo-)intransitive verbs like lachen'to laugh', lezen'to read' and voetballen in (50a), intransitive PO-verbs like spreken (over)'to talk about' in (50b), and verbs with a clausal direct object like vertellen'to tell' in (50c).

The primed examples in (50) show that, since impersonal passives lack a subject (nominative DP), expletive er'there' can be inserted. In main clauses, this is normally obligatory unless some topicalized constituent occupies the sentence-initial position. If the topicalized phrase is an adjunct, as in (51), er is optional.

If the topicalized phrase is an internal argument, as in (52), er is often obligatorily omitted; this holds especially if the internal argument has the form of a clause.

The difference between constructions with and without 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 (51) and (52), the presuppositions are the topicalized phrases, but topicalization is not a prerequisite for dropping er, as is clear from the fact that er can also be omitted in the embedded clauses in (53), in which topicalization is excluded; 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 especially clear from the examples in (54). These examples show that the pronominal indirect object mij'me' blocks expletive er if it does not occur in sentence-initial position. This effect is due to the fact that the referents of referential personal pronouns are normally part of the presupposition of the clause. The numbers in square brackets support the judgments given in (54) by providing the results of a Google search (7/24/2011) on the strings [er werd/is mij verteld], [dat er mij verteld werd/is], [dat er mij werd/is verteld], and [dat mij verteld werd/is]/[dat mij werd/is verteld].

With regard to (50c) it can further be noted that active clauses with a clausal direct object give rise to the impersonal passive only if there is no anticipatory pronoun. In other words, example (55a) only gives rise to the personal passive in (55b), 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 on the basis of 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.