Auxiliary + Null Copula

In [#!lapointe80!#] the copula is treated as an auxiliary verb that takes as its complement a VP headed by a passive verb, a present participle, or a null verb (the true copula). This verb may then take AP, NP or PP complements. The author points out that there are many languages that have been analyzed as having a null copula, but that English has the peculiarity that its null copula requires the co-presence of the auxiliary be.