Modal verbs may take a complement without a verb, so that it seems as if the modal directly mediates a predication relation between a predicate and a subject. So the modal verb seems to function as a copula, see also intransitive complementive predication, transitive complementive predication and complementive. In (1) is an example of verb ellipsis governed by a modal:

In this particular example, the Frisian modal is able to license or give rise to a motional interpretation, rendering the infinitive of the motional light verb gean go optional:

The same phenomenon is also found inside non-finite clauses, in which the presence of the non-finite complementiser om for can compensate the absence of a (light) verbfor , suggesting that the non-finite complementiser shares some property (say, modality) with modal verbs. There are also verbs disallowing light verb ellipsis inside their complement. It seems that light verb ellipsis is subject to a semantic requirement saying that the verbless complement must be nonveridical. In addition, non-finite clauses resist verb ellipsis in case they have an impoverished representation, which is the case when they are directly governed by the verb.