Lesson 29 · Review

Passive -iō Verbs and the Infinitive — vocabulary, rules, and a self-check

IVocabulary

Nine words for the oracle's warning: a danger in this place, a care that must be borne — yet the town will be conquered, nevertheless.

superō, -āreconquer, overcome
cūra, -ae, f.care, trouble
locus, -ī, m.place, spot (plural loca, n.)
perīculum, -ī, n.danger, peril
tamenyet, nevertheless
with abl.: down from; concerning
perwith acc.: through
if
semperalways (review)

IIThe Passive of -iō Verbs

One verb class is left to make passive: the -iō verbs like capiō. They hold no surprises — the passive of capiō follows audiō in the present's endpoints and regō in the middle.

PersonPresentImperfectFuture
1 sg.capiorcapiēbarcapiar
2 sg.caperiscapiēbāriscapiēris
3 sg.capiturcapiēbāturcapiētur
1 pl.capimurcapiēbāmurcapiēmur
2 pl.capiminīcapiēbāminīcapiēminī
3 pl.capiunturcapiēbanturcapientur
Rule 1 — capior and capiuntur follow audior

At the two ends of the present — the first singular and the third plural — the -iō verb keeps its -i- exactly as audiō does: capior (I am taken), capiuntur (they are taken). Everything between behaves like regor.

capior · caperis · capitur · capimur · capiminī · capiuntur

Rule 2 — The 2nd singular keeps its -e-

Just as the third conjugation wrote regeris, not regiris, the -iō present second singular is caperis (or capere) — never capiris. The imperfect and future are ordinary, with the familiar -bā- and no -bi-.

caperis ✓  ·  capiris ✗

IIIThe Present Infinitive

The infinitive names the verb with no person or number — amāre, "to love." The active adds -re to the present stem; the passive is built straight from that active form.

Conj.ActivePassive
Iamāre — to loveamā — to be loved
IImonēre — to advisemonē — to be advised
IIIregere — to ruleregī — to be ruled
III (-iō)capere — to takecapī — to be taken
IVaudīre — to hearaudī — to be heard
Rule 3 — Active infinitive = present stem + -re

Add -re to the present stem for every conjugation: amā-re, monē-re, rege-re, audī-re. The one irregular is sum, whose infinitive is esse — and sum has no passive at all.

amāre · monēre · regere · capere · audīre  ·  sum → esse

Rule 4 — Passive infinitive: final -e, but 3rd conj. -ere

To make the passive infinitive, change the active's final -e to : amāre → amārī, monēre → monērī, audīre → audīrī. The third conjugation has no long vowel to lean on, so the whole -ere collapses to : regere → regī, capere → capī.

amā · monē · audī  ·  regī · capī

IVThe Present Imperative & the -re Collision

The imperative gives a command. The active you have met; here is the passive beside it — and a warning about one form that wears three hats.

Conj.Act. sing.Act. plur.Pass. sing.Pass. plur.
Iamāamāteamāreamāminī
IImonēmonētemonēremonēminī
IIIregeregiteregereregiminī
III (-iō)capecapitecaperecapiminī
IVaudīaudīteaudīreaudīminī
Rule 5 — The passive imperative

The passive singular ("be thou loved") is amāre, monēre, regere, capere, audīre; the plural ("be ye loved") is amāminī, monēminī, regiminī, capiminī, audīminī — the same -minī you saw in the indicative and no other passive ending.

regere (be thou ruled) · regiminī (be ye ruled)

N.B. — one -re, three jobs

A form like amāre can be the active infinitive ("to love"), the passive imperative singular ("be thou loved"), or — in a longer sentence — even an indicative. The ending alone cannot decide; only the sentence around it can. Mind the plural, though: the passive imperative plural amāminī is unmistakable.

amāre = to love · be thou loved · …

VSelf-check

Six out of six before you start the exercises.

Question 1

In capior, what is the subject doing?

Right. capior is the present passive first singular, "I am taken": the -or ending marks the passive, just as in regor and audior. The active "I take" is capiō.

Not quite — the -or ending is passive. Compare active capiō ("I take") with passive capior ("I am taken").

Question 2

Which is the present passive infinitive of regō ("to be ruled")?

Right. The third conjugation has no long stem-vowel, so the whole -ere collapses to : regere → regī. regere is the active infinitive, and regerī is the wrong form you get by naively swapping only the final -e.

Not quite — for the third conjugation the entire -ere becomes , not just the final vowel.

Question 3

What is the present passive infinitive of amō ("to be loved")?

Right. For the first, second, and fourth conjugations you just change the active's final -e to : amāre → amārī. amāre is the active infinitive, and amērī alters a vowel that should stay -ā-.

Not quite — keep the long -ā- of amāre and change only the final -e to .

Question 4

In a sentence with no other clues, the form capere could be…

Right. The present passive imperative singular is spelled exactly like the present active infinitive — capere is both "to take" and "be thou taken." Only the surrounding sentence tells them apart. (The passive infinitive would be capī.)

Not quite — recall the lesson's warning: the passive imperative singular and the active infinitive share the same -re form.

Question 5

From audiō ("hear"), which form is the passive imperative plural, "be ye heard"?

Right. The passive imperative plural takes -minī: audīminī, "be ye heard." audīte is the active plural command ("hear ye!"), and audīrī is the passive infinitive ("to be heard").

Not quite — the passive plural imperative ends in -minī. audīte is active and audīrī is an infinitive.

Question 6

What is the present infinitive of sum?

Right. sum is irregular: its present infinitive is esse ("to be"), and because it has no passive voice, there is no passive infinitive to form.

Not quite — sum does not add -re to a stem. Its infinitive is the irregular esse, with no passive.

Answered correctly: 0 / 6