The correlative measure correlation is asymmetric. The example in (1) involves a primary measure, a litre of milk, which is assigned a secondary value, in this case a monetary value, of 81 cents. The primary measure phrase is preceded by the definite article, whereas the secondary measure phrase contains a cardinal value. In the example above, the preposition is followed by two Noun Phrases (NPs). The two NPs need not occur adjacent to each other, as the following examples show:

The two measure NPs may also occur in a simple copular construction, but in that case the primary measure phrase must feature the indefinite article:

If the definite article is used, the suggestion arises that a specific litre of milk is involved, which is not the intended reading. The construction involves a generic quantification, seeing that every litre of milk costs 81 cents. Generic quantification, in turn, may be viewed as a subtype of universal quantification. The use of the definite article with the primary noun is grammatical if the primary NP does not occur in subject position, as in the example above, but in adjunct position, as in the example below:

The preposition per per is preferred where the use of the definite article is ungrammatical. This is the case when the primary measure noun is animate. In that case, the primary noun occurs without any article following the preposition per per:

However, the construction with the definite article is possible with the noun man man:

Presumably, phrases like per persoan per person are borrowed as a whole from Dutch. The high frequency of the phrase per persoan (due to its popularity in Dutch) blocks the phrase de persoan, although it does not block the native phrase de man. Nevertheless, de man loses out against the high frequency of per persoan and, more likely, it also loses out because de man can have other interpretations as well, whereas per persoan cannot. Phrases which are more specific are often borrowed in a minority language. A case in point is the borrowing of the reflexive zich himself instead of using the simple pronoun as a lexical anaphor. Correlative constructions may also involve the frequency of an event within a time span. In that case, the primary NP retains the definite article, but it shows up in an Adposition Phrase (PP):

Incidentally, the noun denoting frequency remains in the singular, as is not uncommon for measure nouns following a numeral. There is an alternative construction for the expression of frequency within a time span. It is also possible for the primary measure NP to drop the definite article and carry the suffix -s:

Other examples are jiers yearly, deis daily, moarns in the morning. Absent are *oeres hourly, *moannes monthly. The latter class of nouns has a stem which ends in a schwa, whereas the former class of nouns does not; see Dyk (2011).