[1003.] (1 c.) The following verb in -ēre has the perfect stem in -v- ([869]), and the perfect participle in -itus ([910]):

ab-oleō, destroyab-olēreab-olēvīab-olitus

PERFECT STEM IN -u-.

[1004.] (2 a.) Most verbs in -ēre have the perfect stem in -u- ([874]), and the perfect participle, when used, in -tus, which is usually preceded by a short i ([910]): as,

doceō, teachdocēredocuīdoctus
habeō, havehabērehabuīhabitus

So also post-habeō; other compounds have i for a: as, pro-hibeō, pro-hibēre, pro-hibuī, pro-hibitus; twice contracted, prōbet, prōbeat (Lucr.). Compounds with and prae are regularly contracted, dēbeō, praebeō, &c.: but in Plautus once de-hibuistī, and regularly prae-hibeō, &c., throughout.

mereō, earnmerēremeruīmeritus

Often deponent ([800]): mereor, merērī, meritus.

misceō, mixmiscēremiscuīmixtus, mistus

The present stem is an extension of the suffix -sco|e- ([834]); -sc- of the present runs over into the perfect.