Adverbial phrases that modify the full clause can be used in the syntactic frame: Het is adverb zo dat clause, as in (11).

This is illustrated in example (12) for the modal adverb waarschijnlijk'probably'. Note that the examples in (13) show that this test is also applicable to discourse particles like toch.

      Example (12b) is also acceptable without the element zo, but this does not mean that this element is optional in the paraphrase. Example (14a) shows that the clausal adverb waarschijnlijk can neither undergo comparative formation nor be prefixed with the negative element on-. The same facts are found in the paraphrase in (14b), but not in (14c), in which zo is omitted.

The difference between (14b) and (14c) is that the adjective acts as an adverb in the former, but as an adjectival predicate that takes a clausal subject in the latter case (cf. Section 6.5), as was actually already suggested by the glosses in (14). This strongly suggests that zo is obligatory in the right-hand part of the schematic representation in (11), which is also supported by the fact that toch, which cannot be used predicatively, cannot be omitted in (13b).

Clauses that contain a VP adverb can be paraphrased by placing the adverb in a coordinated ... en pronoun doet dat adverb clause, in which the pronoun refers to the subject of the first conjunct. A schematic representation of this paraphrase is given in (15), in which coreference is indicated by means of coindexing. The examples in (16) illustrate this test for the manner adverb snel'fast'.

The two subsections above have discussed the semantic tests for distinguishing clause and VP adverbs. The examples in (17a) and (17b) show that the two paraphrases are often mutually exclusive: modal adverbs like waarschijnlijk cannot be used in an ... en pronoundoet datadverb clause, and manner adverbs like snel cannot be used in the het is adverb zo dat ... frame.

However, this does not hold for all adverbs. Adverbs of time like morgen'tomorrow', for example, can often be used both as a sentence adverb and as a VP adverb, which is also reflected in that they may either precede or follow adverbs like waarschijnlijk, which must be interpreted as clausal adverbs according to the adverb test in the primed examples.