The modal adjectives in (159) are comparable to modal adverbs in that they express some notion of modality: vermeendalleged/supposed in (159a) expresses that the person we are talking about has been mistaken for or is supposed to be the culprit, potentieelpotential in (159b) conveys that the thing we are talking about may turn out to be a counterexample, and eventueelpossible in (159c) expresses that Peter may possibly leave. The primed examples show that modal adjectives cannot be used predicatively because they are not set-denoting.

The second subclass consists of amplifiers like echttrue, and absoluutabsolute in (160), which scale upwards from an implicitly assumed norm. These adjectives do not attribute any property to the head noun, but emphasize that the description given by the noun phrase applies to the subject of the copular clause. This means that the adjectives are clearly not set-denoting, which correctly predicts that they cannot be used in the predicative position of the primed examples. The adjectives are clearly related to the adverbs in the doubly-primed examples, which have a similar amplifying meaning.

Other attributive modifiers with a degree function are adjectives indicating size, such as grootbig or enormenormous. Example (161a) illustrates the use of groot as a regular set-denoting adjective, and (161b) illustrates its use as a degree modifier. That the two cases are different is immediately clear from the fact that in (161a) groot can be replaced by its antonym klein, but not in (161b). This also shows that the degree modifiers are amplifiers; cf. Morzycki (2009) and Hoeksema (2013:386).

That the degree modifier grootbig is not a regular set-denoting adjective is also clear from the fact that it cannot be used as a predicate in a copular construction: while (161a) entails (162a), (161b) does not entail (162b) but (162b'), i.e. example (161b) asserts something not about Jan’s size but about his idiocy/folly.

Size adjectives that function as degree modifiers, such as grootbig, differ from degree adjectives like echttrue and absoluutabsolute in that they retain all the properties of a regular adjective. For example, groot can itself be modified by a degree modifier such as enorm, and can undergo comparative and superlative formation.

Finally, note that the form of degree modification discussed here is not easily performed by categories other than adjectives: we do find PP-modifiers as in (164), but these are clearly idiomatic in nature.

The third subclass consists of quantifiers like gedeeltelijkpartial, halfhalf, volledigtotal in (165). With the possible exception of the last example, quantifiers cannot be used predicatively. However, they are clearly related to the adverbs in the doubly-primed examples.

The fourth subclass involves restrictors such as those in (166); they restrict the reference of the noun but, like the cases discussed in the previous subsections, they cannot be used predicatively (with the intended meaning). They differ from those classes, however, in that the restrictors have no adverbial counterpart.

Time adjectives like gewezen/voormalig/vroegerformer, huidigpresent(day), toekomstigfuture, and vorigeprevious may also be part of this class.

Many adjectives do not seem to fall into a well-defined class, but they do seem to be related to adverbs. Some typical examples are given in (168); observe that the nouns are all deverbal.

Some more or less idiomatic cases in which the relation of the attributive adjectives to the adverbially used adjectives is less direct are given in (169). Note that these adjectives can also be used predicatively, but then the meaning is slightly different. In this respect they are similar to the adjectives discussed in Subsection VI.

Some set-denoting adjectives can be used attributively in a non-qualifying way, which is excluded when they are used predicatively; the predicatively used adjectives in the primed examples in (170) cannot be interpreted in the same non-qualifying way as the attributive adjectives in the primeless examples. Example (170c'') shows that these adjectives cannot be used adverbially either. Examples of this kind are more or less idiomatic.

To conclude, compare the examples in (170a&c) with those in (171a&b); the latter do seem to behave like set-denoting adjectives, since they yield more or less acceptable results with the intended reading in the copular construction.