There’s a great comment by qroqqa on rumoured, which, lest it drift by too quickly, deserves to be highlighted. It starts:

“A highly unusual verb in Present-day English: it has only this one verb form. Although it was historically a full verb with all its parts (‘Come hither Catesby, rumor it abroad, That Anne my Wife is very grieuous sicke.’—Richard III, IV.ii), for most of us today it can only be a past participle.”

Read the rest on rumoured. And thanks, qroqqa, for the insight.