Cāsus Datīvus

The dative (cāsus datīvus) marks the indirect participant of an action — the one to/for whom something is done. From this core meaning radiate many idiomatic uses. Latin recognizes two branches:

(a) Indirect object: the recipient or beneficiary of a transitive verb's action. Goes with verbs of giving, telling, showing, promising, entrusting. dat librum mihi "he gives the book to me".

(b) Reference / Interest: the person or thing affected, interested, evaluated, possessed by, or impacted by the action. Goes with linking verbs and many idioms. tibi est liber "you have a book" (lit. "the book is to you").

Latin is unusually rich in dative usages because it has no preposition for "to/for" — the case alone carries the meaning, and idiomatic extensions abound. There are at least nine recognized dative uses in classical syntax: indirect object, separation (rare), reference, advantage/disadvantage, possession, agent (with passive periphrastic), purpose ("two datives"), ethical, with adjectives.

The dative is the indirect object after verbs of giving, telling, showing, promising, entrusting, sending, denying: dō, dōnō, mittō, dīcō, narrō, scrībō, ostendō, mōnstrō, polliceor, prōmittō, mandō, committō, crēdō, negō, nūntiō.

The direct object is in the accusative; the recipient in the dative: magister puerīs librōs dat "the teacher gives books to the boys" (acc. librōs, dat. puerīs). When passivized, only the accusative becomes nominative; the dative remains: puerīs librī dantur "books are given to the boys".

The dative often translates as "to/for" + indirect object in English, but Latin is more flexible: a dative may follow many verbs that English construes with a prepositional phrase or a different case.

Several Latin intransitive verbs govern the dative where English uses a direct object — a notable feature of Latin idiom that beginners often miss.

Group 1 — Verbs of helping, harming, pleasing, displeasing, trusting, distrusting, commanding, obeying, serving, resisting, persuading, sparing, pardoning, envy:

auxilior tibi "I help you"; noceō tibi "I harm you"; placeō tibi "I please you"; displiceō tibi "I displease you"; crēdō tibi "I trust/believe you"; diffīdō tibi "I distrust you"; imperō tibi "I command you"; pāreō tibi "I obey you"; serviō tibi "I serve you"; resistō tibi "I resist you"; persuādeō tibi "I persuade you"; parcō tibi "I spare you"; īgnoscō tibi "I forgive you"; invideō tibi "I envy you".

Group 2 — Verbs compounded with prefixes ad-, ante-, com-, in-, inter-, ob-, post-, prae-, prō-, sub-, super- often take the dative (the prefix's directional force "transfers" to a dative recipient): adsum tibi "I am present to you / I support you"; occurrō tibi "I meet you"; praeficiō tē exercituī "I appoint you over the army"; impōnō hoc illī "I lay this on that"; antecēdō tibi "I excel you".

In passive constructions, these verbs can become impersonal: mihi parcitur "I am spared" (lit. "it is spared to me"); tibi crēditur "you are believed". The dative cannot become subject in passive — only the verb retains the construction.

Dative of advantage / disadvantage (datīvus commodī / incommodī) indicates the person for whose benefit (or to whose detriment) something is done. It is the most expansive dative use, often translatable as "for, to" but sometimes only as a possessive or no preposition at all in idiomatic English.

tibi labōrō "I work for you / for your sake"; tibi nōcent "they harm you / they are harmful to you"; nōn sibi sed patriae nātus est "he was born not for himself but for his country" (Cicero, on the ideal citizen).

Dative of reference marks the person concerned or affected — close to "as far as X is concerned": mihi quidem placet "to me at any rate it is pleasing"; tibi sapiō "I am wise (in your opinion)"; haec tibi narrō "I tell you this (for your information)".

Ethical dative: a special variant expressing the speaker's emotional involvement (rare in elevated prose, common in colloquial Latin and drama). quid mihi Celsus agit? "What's Celsus doing for me / from my perspective?"; quid tibi vīs? "What do you want / what's the matter with you?".

Dative of possession: with sum, the possessor is in the dative, the thing possessed in the nominative. This is a quintessentially Latin construction with no exact English parallel: liber est mihi "I have a book" (lit. "a book is to me / for me"); multī amīcī sunt eī "he has many friends"; nōmen est mihi Mārcus "my name is Marcus" (lit. "the name is to me Marcus"); ūxor mihi Cornēlia est "my wife is Cornelia".

The Latin construction emphasizes that the possessed thing exists or is present "in connection with" the possessor — a slightly different conceptualization from habeō "I have" (which the language also offers). The dative-of-possession idiom is preferred for fixed attributes, names, family relations, and qualities.

Dative of agent: with the passive periphrastic (gerundive + sum) and (rarely) the perfect passive participle, the agent is in the dative. liber legendus est mihi "the book must be read by me" → "I must read the book"; cōnsulendum est tibi "you must take counsel". This is the standard Latin idiom for obligation, central to Cicero's prose.

For non-periphrastic passive, the agent is in ā / ab + ablative (Lectiō XXVIII).

Dative of purpose / "two datives": a final dative pairs with another (person) dative to express purpose or effect: cui bonō? "to whose benefit?" (Cicero's famous forensic question); auxiliō mihi "as help to me / for my help"; hoc tibi auxiliō erit "this will be a help to you / for your help" (purpose-dat. auxiliō + person-dat. tibi); cōpiae nōbīs praesidiō sunt "troops are a protection for us".

Adjectives governing the dative denote nearness, fitness, friendliness, similarity, equality, or their opposites:

Nearness: proximus mihi "nearest to me"; vīcīnus tibi "neighbor to you".
Fitness/Suitability: aptus pugnae "fit for battle"; ūtilis bellō "useful for war"; idōneus mihi "suitable for me".
Friendliness/Hostility: amīcus tibi "friendly to you"; inimīcus mihi "unfriendly to me".
Similarity/Equality: similis patrī (also gen.) "like the father"; aequālis tibi "equal to you"; commūnis nōbīs "common to us".
Opposite: contrārius hīs "opposite to these".
Trust/Faith: fīdus mihi "loyal to me"; cārus omnibus "dear to all".

Some adjectives accept either dative or genitive with shades: similis patrī (close personal resemblance, dat.) vs similis patris (more abstract/formal, gen.).

Impersonal verbs governing dative: licet mihi "it is permitted to me / I may"; placet nōbīs "it pleases us, we resolve"; libet, displicet, prōdest, obest, expedit, convenit: all take a person in the dative with infinitive or noun-clause complement.

licet mihi īre "it is permitted to me to go = I may go"; placet senātuī ut bellum gerātur "it pleases the senate that war be waged".