Verbs by 3rd Principal Part
Class A: Perfects in -vī or -uī
The most regular way of forming the perfect tense, especially for first, second, and fourth conjugations.
Remember that v and u are the same letter in Latin, just that it’s written as v when pronounced as a
consonant and u when pronounced as a vowel.
-vī (add to present stem including its final vowel)
1st
amō, amāre, amāvī, amātum
cēnō, cēnāre, cēnāvī, cēnātum
cōgitō, cōgitāre, cōgitāvī, cōgitātum
creō, creāre, creāvī, creātum
culpō, culpāre, culpāvī, culpātum
dēmonstrō, dēmonstrāre, dēmonstrāvī, dēmonstrātum
errō, errāre, errāvī, errātum
laudō, laudāre, laudāvī, laudātum
necō, necāre, necāvī, necātum
satiō, satiāre, satiāvī, satiātum
servō, servāre, servāvī, servātum
cōnservō, cōnservāre, cōnservāvī, cōnservātum
superō, superāre, superāvī, superātum
tolerō, tolerāre, tolerāvī, tolerātum
vocō, vocāre, vocāvī, vocātum
4th
audiō, audīre, audīvī, audītum
-uī (add to present stem without its final vowel)
2nd
dēbeō, dēbēre, dēbuī, dēbitum
doceō, docēre, docuī, doctum
habeō, habēre, habuī, habitum
moneō, monēre, monuī, monitum
terreō, terrēre, terruī, territum
valeō, valēre, valuī, valitūrum
Avoid lots of u/v’s in a row
1st
juvō, juvāre, jūvī, jūtum — juvāvī would be awkward to pronounce;
because a consonant (v) gets dropped, the preceding vowel gets lengthened to
compensate (this is called “compensatory lengthening”)
Irregulars
irr
sum, esse, fuī, futūrum — the root changes completely, but it still has a -uī ending
possum, posse, potuī
Class B: Perfects in -sī
The s can combine with the final consonant of the stem in weird ways.
Remember that palatal mute (g, c) + s = x, and that the combination -ns- lengthens the preceding vowel.
2nd
maneō, manēre, mānsī, mānsum
4th
sentiō, sentīre, sēnsī, sēnsum
3rd
mittō, mittere, mīsī, missum — compensatory lengthening for lost dental mutes
āmittō, āmittere, āmīsī, āmissum
gerō, gerere, gessī, gestum
scrībō, scrībere, scrīpsī, scrīptum
dīcō, dīcere, dīxī, dictum
dūcō, dūcere, dūxī, ductum
intellegō, intellegere, intellexī, intellectum
trahō, trahere, trāxī, tractum —yeah, the vowel length is weird
vīvō, vīvere, vīxī, vīctum
Class C: Reduplicated Perfects
Reduplication happens all the time in Greek, but rarely in Latin. There are complex rules that explain
reduplication, but there are so few of these verbs that learning the rules is pointless. Just memorize the
principal parts and save yourself the pain of learning the explanation behind them.
1st
dō, dare, dedī, datum — weak stem: d; add d + e; result: de + d = dedī
3rd
cadō, cadere, cecidī, cāsūrus — weak stem: cid; add c + e (for a); result: ce+cid = cecidī
discō, discere, didicī — weak stem: dic (drop s); add di; result: di+dic = didicī
Class D: Lengthen Weak Stem and add -ī
Drop any infixes and lengthen the stem vowel before adding -ī. Drop any final vowel on the stem The
weak stem vowel a changes to e, lengthens to ē. Frequent for third conjugation -iō verbs.
2nd
videō, vidēre, vīdī, vīsum
3rd
agō, agere, ēgī, actum — stem vowel a changes to e, lengthens to ē
vincō, vincere, vīcī, victum — n (infix in present) drops
3rd io capiō, capere, cēpī, captum —a changes to e, lengthens to ē
faciō, facere, fēcī, factum —a changes to e, lengthens to ē
fugiō, fugere, fūgī, fugitūrus
4th
veniō, venīre, vēnī, ventum
inveniō, invenīre, invēnī, inventum