The passive matrices of English infinitival complement clauses: Evidentials on the road to auxiliarihood?

English verbs of the believe type, which display variation between that-complements and infinitival complements, more often combine with infinitives as passives than as actives. Though there are good information/thematic structural reasons for this (Noël 1998b), the higher frequency of passive matrices could also be a concomitant of a grammaticalization process as a result of which (some of) these matrices are turning into auxiliary-like evidentials. Anderson’s (1986) four-part definition of true (grammaticalized) evidentials is used to establish whether they can qualify as such. The fact that passives are more tolerant of lexical (even dynamic) infinitives than actives (which prefer be and statives) is adduced as evidence of grammaticalization. Individual instances of the passive pattern are differentiated using three criteria of grammaticalization: frequency, expansion and intraparadigmatic variability.