Intellego: To Understand | Latin Grammar

Intellegō means “understand,” “perceive intellectually,” “realize,” or “discern.” Its principal parts are intellegō, intellegere, intellēxī, intellēctum. Three visible bases must be learned: present intelleg-, perfect intellēx-, and supine intellēct-.

The spelling intellegō reflects the editorial convention used here. Classical sources also show intelligō (orthographic variant), but a learner should not mix the two spellings randomly inside one paradigm.

Complete Active Paradigm

Tense	1st sg.	2nd sg.	3rd sg.	1st pl.	2nd pl.	3rd pl.
Present	intellegō	intellegis	intellegit	intellegimus	intellegitis	intellegunt
Imperfect	intellegēbam	intellegēbās	intellegēbat	intellegēbāmus	intellegēbātis	intellegēbant
Future	intellegam	intellegēs	intelleget	intellegēmus	intellegētis	intellegent
Perfect	intellēxī	intellēxistī	intellēxit	intellēximus	intellēxistis	intellēxērunt / intellēxēre
Pluperfect	intellēxeram	intellēxerās	intellēxerat	intellēxerāmus	intellēxerātis	intellēxerant
Future perfect	intellēxerō	intellēxeris	intellēxerit	intellēxerimus	intellēxeritis	intellēxerint

Readers may also meet contracted perfect forms: intellēxtī for intellēxistī occurs in comedy and Cicero, while early comedy can even use intellēxēs for intellēxissēs. They belong to the intellēx- perfect system and are forms to recognize, not the safest default for prose composition.

Subjunctive	1st sg.	2nd sg.	3rd sg.	1st pl.	2nd pl.	3rd pl.
Present	intellegam	intellegās	intellegat	intellegāmus	intellegātis	intellegant
Imperfect	intellegerem	intellegerēs	intellegeret	intellegerēmus	intellegerētis	intellegerent
Perfect	intellēxerim	intellēxerīs	intellēxerit	intellēxerīmus	intellēxerītis	intellēxerint
Pluperfect	intellēxissem	intellēxissēs	intellēxisset	intellēxissēmus	intellēxissētis	intellēxissent

Nunc cōnsilium tuum intellegō.

Now I understand your plan.

Prīmō verba magistrī nōn intellegēbāmus.

At first we did not understand the teacher’s words.

Mox intellegēs cūr tam subitō discesserim.

Soon you will understand why I left so suddenly.

Sī rem intellēxisset, aliter respondisset.

If he had understood the matter, he would have answered differently.

Passive Voice

Tense	1st sg.	2nd sg.	3rd sg.	1st pl.	2nd pl.	3rd pl.
Present	intellegor	intellegeris	intellegitur	intellegimur	intellegiminī	intelleguntur
Imperfect	intellegēbar	intellegēbāris	intellegēbātur	intellegēbāmur	intellegēbāminī	intellegēbantur
Future	intellegar	intellegēris	intellegētur	intellegēmur	intellegēminī	intellegentur
Present subjunctive	intellegar	intellegāris	intellegātur	intellegāmur	intellegāminī	intellegantur
Imperfect subjunctive	intellegerer	intellegerēris	intellegerētur	intellegerēmur	intellegerēminī	intellegerentur

The perfect passive combines intellēctus, -a, -um with sum: intellēctus est, intellēcta erat, intellēctī erunt; intellēctus sit, intellēcta esset. Impersonal intellegitur can mean “it is understood/inferred”; a personal passive means that a statement or sign is understood. A person as the subject of “be understood/appreciated” is especially characteristic of post-Augustan prose, so it should not be projected indiscriminately into every Classical context.

Haec sententia facile intellegitur.

This sentence is easily understood.

Cōnsilium ex paucīs verbīs intellēctum est.

The plan was understood from a few words.

Imperatives and Non-Finite Forms

Present commands are intellege, intellegite. Future intellegitō, intellegitōte, intelleguntō and passive imperatives are (formal/archaic).

Intellege mē nōn īrātum esse.

Understand that I am not angry.

Category	Active	Passive
Present infinitive	intellegere	intellegī
Perfect infinitive	intellēxisse	intellēctum esse
Future infinitive	intellēctūrum esse	intellēctum īrī
Participles	intellegēns; intellēctūrus	intellēctus; intellegendus
Gerund	intellegendī, intellegendō, intellegendum, intellegendō	—
Supines	intellēctum, intellēctū	—

Dīxit sē statim intellēxisse quid accidisset.

He said that he had understood at once what had happened.

Hoc discrīmen omnibus intellegendum est.

This distinction must be understood by everyone.

Direct Objects, Statements, and Questions

A word, intention, argument, sign, or person’s character may be a direct object: verba intellegere, cōnsilium intellegere. A full proposition commonly takes accusative-and-infinitive.

Intellegō tē auxilium petere.

I understand that you are asking for help.

An embedded information question uses an interrogative word with the subjunctive. The mood marks clause type, not uncertainty.

Intellegisne quid hoc verbum significet?

Do you understand what this word means?

The -ne belongs to the direct question “do you understand?”; quid ... significet is the indirect question inside it. See indirect questions.

Understanding from Evidence

Intellegō can mean infer or discern something from signs. The evidence commonly follows ex plus ablative; it is the basis of inference, not a passive agent.

Ex vultū eius intellēxī eum timēre.

From his expression I realized that he was afraid.

The perfect often marks the moment of realization, while the imperfect presents an understanding continuing or gradually forming. Present intellegō can be stative “I understand” or dynamic “I realize,” depending on context.

Semantic Neighbors

Sciō states possession of knowledge; cognōscō often presents acquiring knowledge or recognizing; sentiō begins from perception, feeling, or opinion; intellegō presents grasping a meaning or drawing an inference. Their domains overlap, but they are not interchangeable simply because English sometimes uses “see” or “know” for all four.

Sonitum sentiō, sed quid significet nōndum intellegō.

I perceive a sound, but I do not yet understand what it means.

Historically intellegō is a compound, but Classical Latin treats it as a single high-frequency verb. It does not form a broad productive series of further compounds. The related noun intellēctus and adjective intellegēns preserve its stem patterns.

Understanding Fully, Partly, or Incorrectly

Intellegō does not itself guarantee perfect comprehension. Objects and adverbs can limit its scope: partem intellegere “understand part,” vix intellegere “hardly understand,” rectē intellegere “understand correctly.” Latin can therefore distinguish the moment of realization from the quality of the resulting interpretation.

Verba intellegō, sed argumentum nōndum intellegō.

I understand the words, but I do not yet understand the argument.

Mē male intellēxistī; nōn tē accūsāvī.

You misunderstood me; I did not accuse you.

The second uses male intellegere, literally “understand badly,” where English prefers the lexical verb “misunderstand.” Do not invent a Classical compound merely because English has one.

Negation also has scope. Nōn intellegō eum venīre denies understanding or realization; intellegō eum nōn venīre affirms understanding of a negative fact.

Intellegō eum nōn sponte tacēre.

I understand that he is not silent willingly.

Parsing Diagnostic

Identify intelleg-, intellēx-, or intellēct-. Next ask whether the complement is a direct object, an accusative-and-infinitive statement, or a subjunctive indirect question. An ex phrase normally identifies evidence. Do not translate until the long perfect and supine stems have been assigned to their tense systems.

Common Mistakes

Keeping the present stem in the perfect

❌ Tandem intellegāvī.

Incorrect — the perfect is intellēxī.

✅ Tandem intellēxī.

At last I understood.

Using ut for a statement

❌ Intellegō ut tē abeās.

Incorrect for ‘I understand that you are leaving.’

✅ Intellegō tē abīre.

I understand that you are leaving.

Leaving an indirect question indicative

❌ Nōn intellegō cūr abīs.

Nonstandard for the regular Classical prose pattern, which uses a subjunctive indirect question.

✅ Nōn intellegō cūr abeās.

I do not understand why you are leaving.

Mixing stem spellings

❌ Intelligō, intellegere, intellēxī.

Incorrect as one consistent teaching paradigm — the spellings have been mixed.

✅ Intellegō, intellegere, intellēxī.

The paradigm follows the intelleg- spelling used in this guide.

Key Takeaways

Memorize intellegō, intellegere, intellēxī, intellēctum.
Use accusative-and-infinitive for understood statements and the subjunctive for indirect questions.
Ex plus ablative can mark the evidence from which an inference is drawn.
Keep intelleg- spelling consistent and recognize the intellēx- and intellēct- stems.

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