1. This paper is concerned with Infinitival Perception Verb Complements

of sentences like these has remained controversial in transformational gram-mar (see Declerck (1981b) for a discussion and critique of five different analyses), all grammars apparently agree that structures with IPVC’s can be passivized as shown in the following examples: (1) (a) Bill saw John come to your house yesterday. (b) John was seen (by Bill) to come to your house yesterday. (2) (a) Mary heard Tom sing a song every hour. (b) Tom was heard (by Mary) to sing a song every hour. The claim that (1, b) and (2,b) are the passive counterparts of (1, a) and (2,a) has been made both in traditional grammar (see e.g., Jespersen (1961:315), Quirk et al. (1972:841)) and in transformational grammar (see e.g. Huddleston (1971), Emonds (1976), Horiguchi (1978). In the latter theory the concomitant claim is made that the to which occurs in the passive construction but not overtly in its active counterpart must also be present in the underlying struc-ture of the active IPVC’s but is obligatorily deleted there