Full verbs and auxiliaries are subject to gapping. In the simplest cases, this construction type involves apparent ellipsis within one or more clausal conjuncts under identity with the finite verb or auxiliary of a preceding conjunct. It has often been suggested that the apparent ellipsis must involve at least a verb. Some researchers see in the ellipsis of both full verbs and auxiliaries in this construction support for the claim that they belong to a wider category "verb." However, there is evidence for the argument that this analysis is wrong, and that there are straightforward cases of gapping that do not include a verb or auxiliary. It can be concluded that: (1) gapping may occur in conjoined "small clause" constructions and exclamative clauses, where the ellipsis crucially includes a noun, adjective, adverb, or preposition, suggesting that auxiliaries are not necessarily verbs; and (2) instead, gapping seems to involve an ellipsis that crucially includes a semantic factor or an item that corresponds to a head of an antecedent conjunction or of its major predicate, supporting the view that auxiliaries are heads. (MSE)