906. The perfect participle suffix is #-to-#, nominative #-tus#, #-ta#,
#-tum#, which is often changed to #-so-#, nominative #-sus#, #-sa#,
#-sum# (912).
907. The perfect participle was originally active as well as passive,
and some participles have retained the active meaning: as,
#adultus#, _grown up_; #ēmersus#, _rising out from_; #exōsus#,
#perōsus#, _hating bitterly_; #placitus#, _engaging_; #iūrātus#,
_sworn_, #coniūrātus#, _conspiring_; #prānsus#, _having lunched_,
#cēnātus#, _having dined_, #pōtus#, _drunk_, &c. The perfect participles
of deponents are usually active, but sometimes passive: as, #meditātus#,
_having studied_, or _studied_. Many verbs are not accompanied by a
perfect participle (811), particularly verbs in #-ēre#, with a parallel
adjective in #-idus# (287). Intransitive verbs have usually only the
neuter. A perfect active participle #meminēns# is said to have been used
twice (Plaut., Laev.).