The supplementive use of adpositional phrases is quite restricted. Traditional grammar assumes that only als-phrases and absolute met-constructions are used in this function. Some examples are given in (63); the primeless examples illustrate the relation of “simultaneity” and the primed examples illustrate the relation of material implication; the English translations aim at paraphrasing this difference. We refer the reader to Section A28.3.3 for a detailed discussion of these readings of supplementive phrases.

We may add to this that predicative PP idioms like in de warconfused and over zijn toerenupset can also be used as supplementives; this should not surprise us, because such PP idioms behave in many respects like adjectives; cf. Section 34.3, sub I.

Although traditional grammar analyzes the spatial adpositional phrases in (65) as adverbial phrases, it seems likely that they can also be used as supplementives. Example (65) is at least threefold ambiguous: (i) it can be the case that Jan was in the garden (while observing the moles in the adjacent meadows), or (ii) that the moles were in the garden (while Jan observed them from the kitchen), or (iii) that the entire eventuality of Jan observing the moles took place in the garden. Since the characteristic of a supplementive is that it is predicated of the subject or direct object of the clause, in the first two readings of (65) we should be dealing with the supplementive use of the adpositional phrase; only in the third reading are we dealing with an adverbially used PP.

The suggestion that spatial adpositional phrases can also be used as supplementives is further supported by the fact that they can express a relation of material implication; cf. the examples in (63). For instance, example (66) can be paraphrased as “when Jan is in school, he is always very obedient”. Since, to the best of our knowledge, the contrast between the supplementive and adverbial reading of spatial adpositional phrases is not described in the literature, we will not discuss it any further.

What is extensively described in the literature is the distinction between the supplementive and the adverbial use of the als-phrases; cf. Haeseryn (1997). Consider the examples in (67). In (67a) we have a supplementive als-phrase: the example expresses that Janʼs being a student and Janʼs living in digs took place simultaneously. In (67b), on the other hand, the als-phrase is used as an adverbial phrase expressing a comparison: Jan is living in digs as if he were a student. The two als-phrases differ in that the complement of the supplementive phrase is the bare noun phrase student, while the complement of the adverbial phrase contains an indefinite article: een student. Furthermore, modification by the attributive adjective echt is only possible in the adverbial construction.

Another difference between the two uses of als-phrases is that the nominal complement of the supplementive phrase does not agree in number with the noun phrase of which it is predicated. In order to obtain the supplementive reading in (68a), the complement of als must be singular, despite the fact that the noun phrase of which the als-phrase is predicated (i.e. the subject of the clause) is plural. The complement of the adverbial phrase in (68b), on the other hand, must also be plural.

When the complement of the adverbial phrase denotes a collective, like stelcouple in (67), number agreement is not required for the adverbial reading to occur. The difference between the supplementive and the adverbial use of the als-phrase can again be recognized by the absence or presence of the indefinite article eena.

In the remainder of this section, we will briefly discuss the behavior of the supplementive adpositional phrases with respect to topicalization, scrambling, PP-over-V, and R-extraction. We do not need to say much more about topicalization; the primeless examples in (63) and the (a)-examples in (67) to (69) have already amply demonstrated that topicalization of the supplementive is possible. However, it is more difficult to decide whether scrambling of supplementives is possible, because it is not immediately clear what the base position of the supplementive is. The only thing we know is that it is generated in some position in the middle field of the clause, which is clear from the fact that if the supplementive is not topicalized, it must follow the argument of which it is predicated. In (70a), the supplementive erg aardigvery nice follows both the subject ikI and the object Jan of the clause, and it can be predicated of either of them, although the reading in which the supplementive is predicated of the object Jan is probably the most salient one for most speakers. However, example (70a') clearly shows that an intervening object dat boekthat book does not block the predicative relation between the supplementive als student and the subject ik. Example (70b) shows that if the supplementive precedes the object, it can only be predicated of the subject; this suggests that this order is not the result of scrambling, as scrambling is not expected to change the core meaning of the clause.

If the conclusion that the difference in meaning between (70a) and (70b) is related to differences in the base position of the supplementive phrase is correct, it must be clear that it would be difficult to establish that they can be scrambled. For completeness, note that example (71a) clearly shows that the base position of the supplementive must precede the complementive.

The examples in (72) show that PP-over-V of the supplementive is possible. Like (70a), example (72a) is ambiguous in the sense that the supplementive can be predicated of either the object or the subject of the clause. Again, the reading in which the supplementive is predicated of the object may be the most salient one for some speakers, but (72b) clearly shows that an intervening object does not block the predicative between the supplementive and the subject.

Finally, the examples in (73) show that R-pronominalization and R-extraction are excluded; this should not surprise us, because als never allows this.