Iubeō means “order, command, bid, authorize.” Its principal parts are iubeō, iubēre, iussī, iussum. The present is second conjugation, but perfect iuss- and supine iuss- must be memorized.
Unlike many verbs of requesting and urging, iubeō characteristically takes an accusative person plus infinitive: mīlitēs venīre iubet “he orders the soldiers to come.”
Active Paradigms
| Tense | 1st sg. | 2nd sg. | 3rd sg. | 1st pl. | 2nd pl. | 3rd pl. |
|---|---|---|---|---|---|---|
| Present | iubeō | iubēs | iubet | iubēmus | iubētis | iubent |
| Imperfect | iubēbam | iubēbās | iubēbat | iubēbāmus | iubēbātis | iubēbant |
| Future | iubēbō | iubēbis | iubēbit | iubēbimus | iubēbitis | iubēbunt |
| Perfect | iussī | iussistī | iussit | iussimus | iussistis | iussērunt / iussēre |
| Pluperfect | iusseram | iusserās | iusserat | iusserāmus | iusserātis | iusserant |
| Future perfect | iusserō | iusseris | iusserit | iusserimus | iusseritis | iusserint |
| Subjunctive | 1st sg. | 2nd sg. | 3rd sg. | 1st pl. | 2nd pl. | 3rd pl. |
|---|---|---|---|---|---|---|
| Present | iubeam | iubeās | iubeat | iubeāmus | iubeātis | iubeant |
| Imperfect | iubērem | iubērēs | iubēret | iubērēmus | iubērētis | iubērent |
| Perfect | iusserim | iusserīs | iusserit | iusserīmus | iusserītis | iusserint |
| Pluperfect | iussissem | iussissēs | iussisset | iussissēmus | iussissētis | iussissent |
Dūx mīlitēs manēre iubet.
The commander orders the soldiers to remain.
Magister puerōs tacēre iubēbat.
The teacher was ordering the boys to be quiet.
Crās tē ad mē venīre iubēbō.
Tomorrow I shall order you to come to me.
Cōnsul portās claudī iussit.
The consul ordered the gates to be closed.
Passive Voice
| Tense | 1st sg. | 2nd sg. | 3rd sg. | 1st pl. | 2nd pl. | 3rd pl. |
|---|---|---|---|---|---|---|
| Present | iubeor | iubēris | iubētur | iubēmur | iubēminī | iubentur |
| Imperfect | iubēbar | iubēbāris | iubēbātur | iubēbāmur | iubēbāminī | iubēbantur |
| Future | iubēbor | iubēberis | iubēbitur | iubēbimur | iubēbiminī | iubēbuntur |
| Present subjunctive | iubear | iubeāris | iubeātur | iubeāmur | iubeāminī | iubeantur |
| Imperfect subjunctive | iubērer | iubērēris | iubērētur | iubērēmur | iubērēminī | iubērentur |
Perfect passive uses iussus, -a, -um with sum: iussus est, iussa erat, iussī erunt; iussus sit, iussa esset.
Mīlitēs manēre iubentur.
The soldiers are ordered to remain.
Lūcia domum redīre iussa est.
Lucia was ordered to return home.
The accusative person of the active becomes nominative in the personal passive and remains the understood subject of the infinitive.
Imperatives and Non-Finite Forms
Present commands are iubē, iubēte; passive iubēre, iubēminī. The (formal/archaic) future imperative has active iubētō (2nd/3rd singular), iubētōte (2nd plural), iubentō (3rd plural), and passive iubētor (2nd/3rd singular), iubentor (3rd plural).
| Category | Active | Passive |
|---|---|---|
| Present infinitive | iubēre | iubērī |
| Perfect infinitive | iussisse | iussum esse |
| Future infinitive | iussūrum esse | iussum īrī |
| Participles | iubēns; iussūrus | iussus; iubendus |
| Gerund | iubendī, iubendō, iubendum, iubendō | — |
| Supines | iussum, iussū | — |
In the compact infinitive forms above, iussum esse and iussūrum esse stand for participles that agree with their accusative subject: for example, eam iussam esse and eōs iussūrōs esse. Future passive iussum īrī, by contrast, contains the indeclinable accusative supine iussum.
Dīxit sē mīlitēs manēre iussisse.
He said that he had ordered the soldiers to remain.
Quod iussum est faciendum est.
What has been ordered must be done.
Accusative Person plus Infinitive
The person commanded is accusative and simultaneously the subject of the infinitive. The infinitive may be active or passive.
Iūdex testem vērum dīcere iussit.
The judge ordered the witness to tell the truth.
Iūdex documenta prōferrī iussit.
The judge ordered the documents to be produced.
When no personal performer matters, passive infinitive fierī or a lexical passive is natural: hoc fierī iubet “he orders this to be done.” See accusative-and-infinitive.
Iubeō versus Imperō and Hortor
Iubeō normally uses accusative plus infinitive. Imperō normally gives the person a dative and uses ut/nē plus subjunctive. Hortor takes an accusative person and commonly ut/nē, but means urge rather than command.
Dūx mīlitēs proficīscī iussit.
The commander ordered the soldiers to set out.
Dūx mīlitibus imperāvit ut proficīscerentur.
The commander commanded the soldiers to set out.
Both are correct; their frames must not be blended.
Negative Orders and Authority
With accusative-and-infinitive, nōn negates the ordered action: eum nōn venīre iubet. Classical prose often prefers vetō “forbid” or a prohibitive command when nonperformance is central. Iubeō can also mean officially decree or authorize (formal/legal), and neuter noun iussum means “an order.”
Compounds and Derivatives
Iubeō has no broad productive set of common Classical compounds. The frequent vocabulary family instead includes neuter iussum “an order” and the fourth-declension noun iussus, -ūs, used especially in ablative iussū “by order” and its negative counterpart iniussū “without orders.” Do not create prefixed verbs by analogy with English “countermand” or “reorder.”
Order, Execution, and Result
The perfect iussit reports that the order was given; it does not guarantee obedience. A second verb states whether the command was carried out.
Dūx mīlitēs manēre iussit, sed illī fūgērunt.
The commander ordered the soldiers to remain, but they fled.
Dūx pontem fierī iussit, atque opus decem diēbus perfectum est.
The commander ordered a bridge to be built, and the work was completed in ten days.
Imperfect iubēbat can portray repeated orders or authority being exercised; perfect iussit presents a particular directive as issued. English “had X do Y” may express either effective causation or a command, so Latin must choose according to whether authority or accomplished result is foregrounded.
Impersonal Orders and Official Formulae
When the action matters more than its performer, iubeō commonly governs a passive infinitive: portās claudī iubet. The thing acted upon is the subject of that passive infinitive.
Senātus lēgātōs statim mittī iussit.
The senate ordered envoys to be sent immediately.
In civic language, populus iubet can mean that the people enact or authorize a proposal (formal/historical). Expressions iussū “by order” and iniussū “without the order” use the ablative of the noun iussus, not a finite verb.
Iussū cōnsulis portae clausae sunt.
By order of the consul, the gates were closed.
Parsing Diagnostic
Identify iubē-, iuss-, and determine voice. In the active, find an accusative person and infinitive; in the personal passive, look for the nominative ordered person with an infinitive. Do not mistake perfect iussit for a present form or replace the irregular stem with iubēv-.
Common Mistakes
Inventing the perfect
❌ Dūx mīlitēs manēre iubēvit.
Incorrect — the perfect is iussit.
✅ Dūx mīlitēs manēre iussit.
The commander ordered the soldiers to remain.
Using ut after iubeō
❌ Iubeō ut Mārcus veniat.
Incorrect as the regular Classical complement of iubeō.
✅ Iubeō Mārcum venīre.
I order Marcus to come.
An ut-clause is attested with iubeō, especially in historical and institutional prose, so it is not impossible Latin. The correction teaches the verb's characteristic and safest Classical frame, accusative plus infinitive.
Giving the commanded person a dative
❌ Mīlitibus manēre iubet.
Incorrect — iubeō takes the commanded person in the accusative.
✅ Mīlitēs manēre iubet.
He orders the soldiers to remain.
Keeping the person accusative in the passive
❌ Mīlitēs manēre iubētur.
Incorrect — plural mīlitēs requires iubentur.
✅ Mīlitēs manēre iubentur.
The soldiers are ordered to remain.
Key Takeaways
- Memorize iubeō, iubēre, iussī, iussum.
- The regular complement is accusative person plus infinitive.
- In the personal passive, the ordered person becomes nominative but remains subject of the infinitive.
- Keep iubeō distinct from dative + ut with imperō.
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