The use of a definite article conveys that the referent set is “identifiable” in the sense of being given in or recoverable from the context. Since restrictive relative clauses serve to restrict the potential number of referents of the antecedent, this implies that the article has scope over both the antecedent and the relative clause. Non-restrictive relative clauses, on the other hand, provide additional information about the referent of the antecedent and do not serve to identify the referent of the antecedent: if this referent is assumed to be identifiable, it will be so independently of the information contained in the relative clause, and the definite article can therefore be assumed to have scope only over the antecedent. This difference in scope can be represented as in (245). In (245a) the relative clause is placed within the NP-domain and thus within the scope of the determiner. In (245b), on the other hand, the relative clause is placed outside the NP to express that it does not affect the denotation of the noun, and thus has no influence on the size of the referent set of the whole DP; cf. Section 17.1.2, sub II, for a discussion of some problems concerning the internal structure of DPs containing non-restrictive modifiers.

In (245a) the choice of the definite determiner depends on the information given by the relative clause: the definite article can be used because the referent of the antecedent (fietsbike) is identifiable due to the fact that the relative clause restricts the set of bikes to exactly one. In (245b), on the other hand, the choice of article does not depend on the information given by the relative clause: the referent of the antecedent is assumed to be identifiable independently of the relative clause.

When the antecedent noun is quantified, the scope of the quantifier varies according to the type of relative clause used: if the relative clause is restrictive, the quantifier has scope over both the antecedent noun and the relative clause; if the relative clause is non-restrictive, only the antecedent falls within the scope of the quantifier. This is illustrated in example (246) for the universal quantifier alleall. The difference in scope here corresponds to a simple difference in meaning: whereas (246b) expresses that all persons present were offered a meal, (246a) implies that only a subset of the persons present (namely, those who came from afar) were offered a meal.

Not all quantified noun phrases allow modification by both types of relative clause. Modification of a universally quantified noun phrase by a non-restrictive relative clause is only possible when the noun phrase denotes a group, as in (246); when we are dealing with a set of singular entities, as in the case of ieder(een)every(one) in (247) or elkevery/each in (248), the modifying relative clause can only be restrictive.

In the case of existential quantifiers like enkelesome, sommigesome and de meestemost, on the other hand, interpretation can be complicated by the fact that the quantifier itself can have two different readings, a purely quantitative one (some/most N) and a partitive one (some/most of the N). First, consider the examples in (249), which involve restrictive relative clauses. As expected, the quantifiers enkelesome and de meestemost have scope over the relative clause: example (249a) asserts that there is a set of books that are marked down and that the speaker bought some of them, and example (249b) that there is a set of clocks that were broken and that the speaker repaired most of them.

The interpretation of the corresponding examples with non-restrictive relative clauses depends on whether the quantifier has a purely quantitative or a partitive reading.

In the purely quantificational reading, the information in the non-restrictive relative clause is taken to apply to the entire quantified set: (250a) asserts that some books were reduced in price and that the speaker bought them, and (250b) that many clocks were broken and that the speaker repaired them. In the partitive reading, on the other hand, there is a certain set of books or clocks that has previously been introduced into the discourse, and the quantified expression refers to a subset of this set. The relative clause, however, does not take the quantified expression as its antecedent, but the original, non-quantified set. In this case the relative clause is given contrastive emphasis and is equivalent in terms of scope relations to the explicit partitive constructions given in (251).

Negative noun phrases behave more or less like the universally quantified noun phrases in (247) and (248) in that they do not allow non-restrictive relative clauses. Some examples are given in (252).

In the primeless examples, the negation expressed by geen and the n- part of the existential quantifier niemand have sentential scope. The interpretation has the general format in (253), where N stands for the property expressed (i.e. the set denoted) by the modified NP and V for the property expressed by the VP. The effect of the restrictive relative clauses in the primeless examples in (252) is that the set denoted by the modified NP is smaller than the set denoted by the unmodified noun, leading to the paraphrases in (253a&b).

The paraphrases in (253) show that the primeless examples in (252) do not exclude the existence of cities that are as beautiful as Amsterdam or of people known to the speaker. Since non-restrictive relative clauses do not affect the referent set of the noun phrase, the primed examples do have these implications, and this is indeed the reason why they are unacceptable; since an empty set has no members about which one can give additional information, the use of a non-restrictive relative clause leads to a contradiction, or at least to a semantically incoherent interpretation. For example, sentence (252a'), is incoherent because it expresses that the members of the empty intersection of the set of cities and the set of entities that are as beautiful as Amsterdam are known to the speaker. Similarly, sentence (252b') should express the nonsensical meaning that the members of the empty set of people known to the speaker like horror movies.

Note in passing that non-restrictive relative clauses differ crucially in this respect from appositives, which can modify negative noun phrases. Example (254), for instance, is perfectly acceptable because the apposition, though added as an afterthought, is still restrictive in nature; cf. the discussion in Section 17.1.3, sub II.

The examples in (256) show that generic antecedents accept both restrictive and non-restrictive relative clauses, although the result is somewhat marked when the generic antecedent is singular, as in (256a'). The restrictive relative clauses in the primeless examples again function to restrict the whole class of entities referred to by the antecedent noun. The non-restrictive relative clauses in the primed examples are used to provide additional information about the referent of the generic antecedent NP, i.e. the entire class of objects denoted.

The examples in (257) show that combinations of specific indefinite antecedents and restrictive relative clauses are perfectly acceptable. The restrictive relative clause serves to restrict the specific referent set of the antecedent, but the use of the indefinite article conveys that the noun phrase fails to uniquely identify the referent set for the hearer, i.e. the resulting set still consists of more than one potential referent set.

Non-restrictive relative clauses, on the other hand, are less easily combined with a specific indefinite antecedent. The sentences in (258), for example, are definitely marked, and may even require an appositive reading of the relative clause; cf. Section 17.1.3.

The sentences in (259) are acceptable, but not on the intended reading. Although the antecedent in these constructions has a specific reference, the (present-tense) relative clauses provide information about the class as a whole. Thus, the most likely interpretation of these examples is one in which the additional information given in the relative clause applies to all cuckoo clocks, not just the one(s) we bought.

That it is not impossible for non-restrictive relative clauses to modify certain indefinite antecedents can be seen from the examples in (260), where the only possible reading is the intended one: the relative clauses provide additional information about the clocks under discussion.

The examples in (261) show that non-specific antecedents accept only restrictive relative clauses. This is not surprising, given the difference in function between restrictive and non-restrictive relative clauses. The speaker can easily use a restrictive relative to narrow down the set of possible non-specific referents: the primeless examples simply exclude all clocks that do not come from Switzerland. However, since the identity of the referents in the referent set of the noun phrase is also unknown to the speaker, the speaker is not able to provide more information about these referents in the form of a non-restrictive relative clause. As a result, the primed examples are only acceptable on a specific or generic reading of the noun phrase.