[854.] There are two kinds of perfect stems: (A.) Some verbs have as perfect stem a root, generally with some modification, but without a suffix ([858-866]). (B.) Some perfects are formed with a suffix, -s-, or -v- or -u- ([867-875]).
[855.] Some perfects of primitives are formed not from a root, but from the present stem without the formative vowel, treated as a root: as, prehendī, seized, from prehend- ([866]); poposcī, asked, fefellī, deceived ([858]); iūnxī, joined ([867]).
[856.] The first person of the perfect ends in -ī, sometimes written ei ([29, 2]). -t, -stī, sometimes written -stei ([29, 2]), -stis, and -mus are preceded by short i; -re is always, and -runt is usually, preceded by long ē: as,
rēxī, rēxi-stī, rēxi-t, rēxi-mus, rēxi-stis, rēxē-runt (rēxe-runt), or rēxē-re.
[857.] Sometimes -t is preceded by long ī: as, iīt, petiīt, REDIEIT ([29, 2]). -runt is sometimes preceded by short e (Plaut., Ter., Lucr., Hor., Ov., Verg., Phaedr.). This is the original form; -ē- is by analogy to -ēre.
(A.) PERFECT STEM WITHOUT A SUFFIX.
[858.] (1.) Some verbs in -ere form their perfect stem by prefixing to the root its initial consonant with the following vowel, which, if a, is usually represented by e; this is called the Reduplicated Perfect, and the first syllable is called the Reduplication: as,
| Perfect Stem. | Verb. | From Theme. |
|---|---|---|
| pu-pug- | pungō, punch | pug- |
| pe-pig- | pangō, fix | pag- |
Other examples are: cadō, fall, cecidī (cad-, [104, c]); pariō, bring forth, peperī (par-, [104, c]); pellō, push, pepulī (pol-, [105, h]); poscō, demand, poposcī ([855]); fallō, deceive, fefellī ([855], [104, c]); see also [923-932]. caedō, cut, has cecīdī ([108, a]); and a few old forms are quoted from verbs having an o or an u in the root with e in the reduplication: as, memordī, pepugī.
[859.] Four verbs with vowel roots also have a reduplicated perfect stem: dō, give, put, dare, dedī; bibō, drink, bibere, bibī; stō, stand, stāre, stetī, and sistō, set, sistere, -stitī, rarely stitī. Also four verbs in -ēre: mordeō, bite, momordī, pendeō, hang, pependī, spondeō, promise, spopondī, tondeō, clip, -totondī. In the root syllable of spopondī, promised, stetī, stood, stitī, set, and the old scicidī, clove, an s is dropped ([173, 2]).