Credo: To Believe

Crēdō means “believe,” “trust,” “suppose,” or “entrust.” Its principal parts are crēdō, crēdere, crēdidī, crēditum. The repeated -d- in the perfect is genuine: the present stem is crēd-, the perfect crēdid-, and the supine crēdit-.

English uses “believe” with a direct object person; Classical Latin normally puts the person trusted or believed in the dative. A proposition, by contrast, is commonly expressed by accusative-and-infinitive.

Complete Active Paradigm

First-person crēdam is future indicative or present subjunctive. A future condition supports “I shall believe”; potential or subordinate syntax supports the subjunctive.

The tables give the productive Classical forms. Early comedy also preserves subjunctives such as crēduam and an isolated perfect crēvī for crēdidī. These are recognition forms, not patterns to extend through the ordinary paradigm.

Passive Voice

Perfect-system passives use crēditus, -a, -um plus sum: perfect crēditus sum, pluperfect crēditus eram, future perfect crēditus erō; perfect subjunctive crēditus sim, pluperfect subjunctive crēditus essem. The participle agrees with a grammatical subject in gender and number.

Passive syntax depends on what the active construction means. A trusted source remains dative, so normal prose uses impersonal mihi crēditur “I am believed” rather than making ego the subject; poets sometimes use personal crēdor or crēditus sum in this sense. By contrast, the accusative subject of a believed proposition can become nominative in the regular personal passive: Caesar vēnisse crēditur “Caesar is believed to have come.” An entrusted thing likewise becomes subject while its recipient stays dative.

In the second example, accusative pecūniam of the active sentence becomes nominative pecūnia; dative amīcō remains dative.

Commands and Non-Finite Forms

Present active commands are crēde, crēdite. The future imperative has crēditō for the second- or third-person singular, crēditōte for the second-person plural, and crēduntō for the third-person plural; it is especially characteristic of laws and precepts. Rare passive imperatives are present crēdere, crēdiminī and future crēditor (second- or third-person singular), crēduntor (third-person plural).

In perfect passive crēditum esse, the participle changes with the infinitive's understood subject. Rare future passive crēditum īrī instead contains the invariant accusative supine crēditum, regardless of that subject's gender or number.

The gerundive construction is impersonal because the trusted person remains dative. English makes “this man” the grammatical subject; Latin preserves the verb’s dative government.

Believing a Person and Believing a Statement

Use dative for the person whose word or reliability receives trust: tibi crēdō. Use accusative-and-infinitive for the proposition accepted as true.

The contrast shows why English word order is a poor guide. Mercātōrī is dative; in the proposition pretium is accusative subject of esse and iūstum agrees with it. See accusative-and-infinitive.

An accusative person is therefore possible when that person is not the trusted source but the subject of a judgment: tē bonum crēdō means “I think you good” and represents tē bonum esse crēdō. It does not replace dative tibi crēdō for “I believe what you say.”

Neuter pronouns can serve as direct objects: hoc crēdō “I believe this.” With a full statement, however, accusative-and-infinitive is the regular Classical structure. Parenthetic crēdō can soften a claim: “I suppose, I think.”

Entrusting Something to Someone

In its older concrete sense, crēdō means “entrust, lend.” The thing entrusted is accusative, the recipient dative. This frame explains the dative used with a person believed: one entrusts confidence to that person.

“Believe In” and Register

English “believe in someone” normally means trust that person; Classical Latin ordinarily uses the dative alone. Crēdere in plus accusative becomes prominent in later Christian Latin (late/religious) and should not be projected mechanically into neutral Classical prose. Belief about a topic can use dē plus ablative, but the exact construction depends on whether the object is a person, claim, or subject matter.

Crēdō has no productive set of high-frequency Classical verbal compounds comparable with ferō or faciō. The uncommon concrēdō, concrēdere, concrēdidī, concrēditum reinforces the concrete sense “entrust, consign”; it is not a general-purpose replacement for crēdō. Words such as incrēdibilis “unbelievable” belong to the derivational family, not to a paradigm of ordinary compound verbs.

Negation and Degrees of Commitment

The placement of nōn distinguishes failure to believe from belief in a negative proposition. Nōn crēdō eum venīre means “I do not believe that he is coming”; crēdō eum nōn venīre means “I believe that he is not coming.” The two may suggest similar expectations in conversation, but their logical structure differs.

Adverbs calibrate commitment: certē crēdō asserts confidence, while vix crēdō marks reluctance or surprise. Parenthetic crēdō often corresponds to English “I suppose,” but it still expresses the speaker’s assessment rather than objective knowledge.

Parsing Diagnostic

Identify crēd-, crēdid-, or crēdit-. Then locate any dative person. If an accusative is followed by an infinitive, parse a believed proposition; if both an accusative thing and dative person occur, test the concrete sense “entrust.” In passive clauses, do not convert the surviving dative into an agent.

Common Mistakes

Making the believed person accusative

Inventing the perfect

Using ut for a believed proposition

Copying English “believe in”

Key Takeaways

• Memorize crēdō, crēdere, crēdidī, crēditum.
• The person believed or trusted is dative; a believed statement normally uses accusative-and-infinitive.
• “Entrust” takes an accusative thing and a dative recipient.
• Passive and gerundive constructions preserve the person in the dative.