Verb frame alternations involve changes in the number and the types of complements selected by the verb. The cases discussed in Section 3.2 are clear cases of verb frame alternations in the intended sense as they involve the demotion, suppression or addition of an external argument by, respectively, passivization, middle formation and causativization. The same thing holds for the NP/PP alternations discussed in Section 3.3, provided that we assume that the PPs in question are selected by the verb. However, Levin (1993) includes a number of cases in her inventory of verb frame alternations for which it is not so clear whether they should indeed be characterized as such (in Dutch at least). Consider the two examples in (527). Pairs like these clearly do not involve verb frame alternations in the sense defined above given that the verb selects two arguments (an agent and a theme) in both cases. Note that coreference is indicated by italics.

Things may be different in the (a)-examples in (528), which Levin refers to as the understood reciprocal alternation and which seems to involve the (optional) suppression of the theme argument. It seems implausible, however, that exhibiting this alternation is a general property of verbs with an agent and a theme given that the primed (b)-example seems to be infelicitous without the reciprocal.

There must therefore be some other difference between verbs like kussen'to kiss' and slaan'to hit'. The relevant difference seems to be that kussen can be combined with a comitative met-PP, whereas this is impossible with slaan.

That this may well be the correct conclusion is strongly suggested by the fact illustrated in (530) that the understood reciprocal alternation is more generally found with verbs allowing a comitative met-PP; Levin refers to this case as the reciprocal alternation.

The question as to whether we are dealing with a verb frame alternation now rests on whether the comitative met-PP is a complement of the verb; we are only dealing with a verb frame alternation if the answer to the latter question is positive. An argument in favor of a positive answer is that the option of having a comitative met-PP clearly depends on the meaning of the transitive verb, but there are also reasons for assuming that the comitative met-PP is an adjunct, just like the instrumental PP met de bal'with the ball' in (531), which does not allow the alternation because it does not have the semantic function of co-agent.

A first reason for assuming that comitative and instrumental met-PPs are both adjuncts is that they can readily be omitted without being semantically understood: the sentence Jan speelde in de tuin leaves entirely open whether Jan is playing with some other person or with some specific object. The second reason is that they both behave like VP-adjuncts, which is clear from the fact that example (531a) can be paraphrased by means of the ... en pronoun doet dat met-PP clause in (532a), irrespective of the nature of the met-phrase. Another reason may be that these met-phrases may both precede the adverbial place adverbs in (532b) in neutral (non-contrastive) contexts, whereas PP-complements normally follow adverbial phrases in such cases; note that we used an embedded clause to illustrate this in order to eliminate the intervention of extraposition. See Section 2.3.1, sub VII, and Section 2.3.4, sub I, for more relevant discussion.

If we are to conclude from these facts that the comitative met-PP is simply an adjunct, we should also conclude that Levin's understood reciprocal alternation is not a verb frame alternation: we are simply dealing with (pseudo-)intransitive verbs. An additional argument against postulating an understood reciprocal verb frame alternation is that the constructions with and without a reciprocal are not semantically equivalent. This is clear from the fact that there is no implication relation between the primeless and primed examples in (533) whatsoever: the primeless examples simply state that Jan and Peter like to kiss/play in general, without there being an implication that they like to do that together; the primed examples, on the other hand, do express that Jan and Peter like to kiss/play together, but they do not imply they like to do that in general, that is, with other individuals.

The conclusion that there is no (understood) reciprocal verb frame alternation holds not only for the cases above with a comitative met-PP but also for other syntactic configurations in which a noun phrase may bind a reciprocal. This holds especially for resultative constructions such as (534), in which the logical subject of the predicative PP can act as the antecedent of a reciprocal embedded in the PP.

The examples in (535) show that the reciprocal construction is also semantically different from the non-reciprocal construction in this case. The primed examples are only possible if the primeless examples are symmetrical in the sense that they allow the two noun phrases to change places: cf. Marie legde de enveloppen bij de brieven'Marie put the envelopes with the letters' versus $Marie legde de voordeur bij de brieven'Marie put the front door with the letters'. This shows clearly that the alternation is determined by the nature of the noun phrases rather than that of the verb.

Similar objections can be raised to other cases that Levin collects under the general denominator of reciprocal alternation like the samen-alternation in (536). Given that the particle samen'together' in (536a'&b') may precede the adverbial phrase and the PP-complement, it is clearly not a verbal particle selected by the verb, and consequently we may safely conclude that we are not dealing with a verb frame alternation. Similarly, it seems that in the (c)-examples the PP and samen have the same syntactic function, viz. that of complementive, and it is therefore again not justified to consider this a case of verb frame alternation.

This section has discussed a number of systematic alternations and considered the question as to whether we are dealing with verb frame alternations in the restricted sense defined earlier, that is, as changes in the number and the types of complements selected by the verb. We concluded that this is not the case for the alternations discussed here, which implies that such alternations are not interesting from a syntactic point of view (which of course leaves open that they may be interesting from, e.g., a semantic point of view).