The two examples in (39) are both perfectly acceptable if there is only one crown prince in the domain of discourse. This implies that the attributive adjectives in (39a) are not needed to restrict the denotation of the noun kroonprinscrown prince, but are added to express additional information about the crown prince: just like the predicatively used adjectives in (39b), the attributive adjectives in (39a) are used to inform the addressee about the fact that the crown prince is tall and fair.

We need not regard the non-restrictive interpretation of (39a) as an exception to the general pattern given in Figure 2, but can simply regard it as a special case of the left-hand representation. Since the noun kroonprins denotes a singleton set, the intersection of the sets denoted by the noun and the two adjectives is either the singleton set denoted by the noun or empty. Since it would not be informative to attribute the properties of being long and fair to the empty set, it is clear that the speaker intends to refer to the singleton set; this gives the false impression that (39a) involves an inclusion relation, when in fact it is a special case of the intersection relation.

Adjectives modifying proper nouns can also receive a non-restrictive interpretation, because proper nouns are not usually used to denote a set, but to refer to an individual. The examples in (40a&b) thus express that de Westerkerk can be characterized as a beautiful church and that Schiphol is a crowded airport. Note that there is a certain tendency for non-restrictive attributive adjectives to be interpreted as epithets; example (40c) is a classic example of this.

Note that proper nouns must always be preceded by a determiner when they are modified by an attributive adjective. For example, the articles in (40b&c) are obligatory, even though the proper nouns in these examples are normally articleless: cf. (*het) Schiphol and (*de) Helena. For further information, see the discussion of the modification of proper nouns in Section N16.1.

There is no a priori reason to assume that non-restrictive readings of attributive adjectives are limited to proper nouns and nouns denoting singleton sets: we expect that, at least in some cases, we will find ambiguous examples where the modified noun denotes a non-singleton set. This is indeed borne out, as the examples in (41) will show. They can all be interpreted as referring to a subset of the noun’s denotation, but they also allow a non-restrictive interpretation, in which case the property denoted by the adjective is attributed to all members of the set denoted by the noun.

For instance, example (41a) can be interpreted in two ways: the restrictive interpretation of the adjective dapperebrave asserts that only a subset of a larger group of soldiers fought to the end; the non-restrictive interpretation of the adjective asserts that all members of the group of soldiers fought to the end, which is why they are called brave. Note that example (41a) is truly ambiguous only in writing, since in speech intonation usually resolves the ambiguity: in the restrictive interpretation the adjective is usually stressed, while in the non-restrictive interpretation it is usually unstressed.

Something similar holds for (41b): in the restrictive interpretation, there are several contextually determined quantities of water with different properties, and it is asserted that it was the cold water that made Peter shiver; in the (more likely) non-restrictive reading, there is only one quantity of water, and we infer that the water made Peter shiver because it was cold. Again, the ambiguity can be resolved by the intonation pattern.

Similar ambiguities can also arise in nominal constructions with a demonstrative or possessive pronoun. Example (44a) can be used as a question asking for a particular pen from a contextually determined set of pens, in which case the adjective is used restrictively to identify the intended object. However, the adjective can also be used when there is only one entity that matches the description of the noun pen, in which case the adjective has a non-restrictive, purely descriptive function; it may help the addressee recognize the object referred to, but it does not serve to identify the intended object. Similarly, example (44b) can be used in a context where the speaker had an old computer that did not work well; in this case, the adjective is used restrictively and emphasized. A non-restrictive interpretation is also possible, in which there is no comparison with other computers involved; the adjective simply provides the additional information that the computer was recently purchased.

The context may also favor the non-restrictive reading. In (45), for example, it is clearly the non-restrictive reading of the adjective that is intended: the message is not that only the well-informed advisors will be happy to help, but that all advisors are well-informed and will be happy to help.

Example (46) shows that certain construction types can also favor the non-restrictive reading. The pseudo-partitive construction van die heerlijke truffels (discussed in Section N17.1.1.6) looks like a PP but actually functions as a noun phrase referring not to a particular subset of truffles but to a particular kind of truffle that is claimed to be delicious. The attributive adjective does not serve to restrict the denotation of the noun, which is presumably already known to the addressee, but is used purely descriptively; we can infer from (46) that the speaker wants to have more truffles of the kind in question because he finds them delicious.

Indefinite noun phrases do not readily permit a non-restrictive interpretation of the attributive adjective; in all of the examples in (47), the adjective restricts the set denoted by the noun, thus (implicitly) contrasting that subset with the remaining members of the set.