Several restrictions on successive cyclic wh-movement appear not to be exclusively linked to general principles of the grammar, but seem to be in some sense lexically determined. It has been pointed out repeatedly that wh-movement of subjects and adjuncts out of complement CPs of factive verbs strongly contrasts with wh-movement of internal arguments out of these CPs (Rouveret, 1980; Kayne, 1981; Zubizarreta, 1982; Adams, 1985):
(1) (a) *Who do you regret/understand/forget likes this book? (= Adams, 1985: (4b))
(b) *How did he deeply regret that his son had fixed the car?
(c) ?Which article did you regret/understand/forget that I had selected?