The (a)-examples in (23) show that proper nouns normally do not allow any form of modification aimed at restricting the number of potential referents: example (23a) is acceptable but only if the attributive adjective is used non-restrictively, that is, provides additional information about the referent of the noun phrase; example (23a') becomes acceptable if the relative clause is preceded by an intonation break, which is the landmark of the non-restrictive use of such clauses. Example (23b) is added to show that if the proper noun itself contains a (restrictive) modifier, this cannot be omitted without the noun phrase losing its status of proper noun.

In some cases a restrictive modifier is allowed, but then it forces a reading in which there is more than one accessible referent which can be referred to by the same proper noun or, to say it differently, adding a modifier is acceptable if unique identification is not possible on the basis of the proper noun alone. This is shown in the examples in (24).

The primeless examples in (25) show that proper nouns cannot be pluralized, unless the proper noun phrase itself is formally plural; example (25b') shows that in the latter case the singular will not be available (at least not as a proper noun).

This differences in syntactic behavior between common nouns and proper nouns can again be accounted for by the fact that proper nouns are supposed to refer “uniquely” within a given context, providing the addressee with sufficient information to identify the intended referent. If the proper noun fails in this respect, as in the examples in (26), pluralization becomes possible.

Unlike common nouns, proper nouns typically are not acceptable with an article in Standard Dutch; they similarly fail to co-occur with demonstrative pronouns or with other determiners. These restrictions are illustrated in (27). It should be noted, however, that in certain southern dialects of Dutch, use of the definite article or a possessive pronoun is acceptable with proper nouns referring to persons: de/onze Jan.

Articles are used when they can be regarded as part of the proper name (sometimes spelt with a capital: De Volkskrant). The examples in (qq) show that in such cases the use of other determiners is still prohibited.

The examples in (28) contain the proper nouns Jansen and Italië and show that restrictive modification requires the addition of a determiner: singular proper nouns denoting an animate object co-occur with a non-neuter determiner like the article de in (28a), whereas singular proper nouns denoting a geographical name take a neuter determiner like the article het in (28b).

If an article is used in combination with proper nouns that themselves already include a definite article, like De Volkskrant in the (a)-examples in (29), the latter is typically left out. This does not hold, however, if the article is an old case form like den in example (29b), which suggests that present-day speakers no longer recognize these elements as articles.

      As illustrated in example (24c), the names of the days of the week can also be used in combination with the definite article and an identifying modifier. When we are referring to a particular day close to the moment of speech, the determiner is normally left out, even if the noun is modified. However, if the intended day is more remote, the definite article is normally used. This is shown in (30).

The indefinite article is also possible, indicating a specific but not further identified, or a nonspecific, Wednesday, as in (31a) and (31b), respectively.

      Proper nouns referring to seasons and names of the months are more restricted with respect to the determiner. The examples in (32) show that the names of the seasons must be preceded by a definite determiner, regardless of whether a restrictive modifier is present or not.

The examples in (33), on the other hand, show that the names of the months cannot be preceded by a definite determiner, again regardless of whether a restrictive modifier is present or not. Note that, for one reason or another, it is not possible to modify the names of months by means of a PP like van 1963; either the proper noun is immediately followed by the year or (more formally) by the PP van het jaar 1963.

The examples in (34) show that neither the names of seasons nor the names of months can be preceded by an indefinite article, again regardless of whether a restrictive modifier is present or not.

      Finally, proper nouns can co-occur with the demonstrative determiner die in the informal expressions given in example (35), which are used to express surprise, usually combined with a touch of admiration (“who would have thought it!”) or commiseration (“poor fellow/girl”). Note that die is the only form available, even if it precedes a +neuter noun like the diminutive in (35b); see Section 5.2.3.2, sub IIE, for more discussion.