Dative with Adjectives

Certain Latin adjectives take a dative complement to name the person or thing toward which their quality is directed: nōbīs amīcus, “friendly to us”; castrīs idōneus, “suitable for a camp”; urbī propinquus, “near the city.” The dative does not agree with the adjective. It completes the adjective’s meaning, much as English uses a shifting set of prepositions—“to,” “for,” “with,” or none at all.

The main adjective classes express fitness, use, friendliness or hostility, nearness, and likeness. The pattern is productive but lexical: you must learn which adjective licenses which complement and which alternatives Classical authors use. There is no honest rule that predicts every choice from English.

For the wider system—including adjectives that instead select a genitive or ablative—see adjectives governing cases.

The governing idea

The adjective describes one noun and points its quality toward another. Keep agreement and government separate.

Idōneus is nominative masculine singular because it agrees with locus. Castrīs is dative plural because it completes “suitable.” The identical dative/ablative plural ending -īs does not make the case genuinely undecidable: the adjective and meaning supply the syntactic evidence.

Inūtilia agrees with neuter plural cōnsilia; reī pūblicae is dative singular. English places “the republic” after “to,” while Latin marks the relation in both words of that noun phrase.

The principal adjective classes

These groupings are semantic aids, not exhaustive rules. For example, facilis and difficilis can take a dative of the person for whom something is easy or difficult, while aliēnus “foreign to, inappropriate for” also participates in related patterns. Although proprius belongs to this semantic family and an attested dative is possible, Classical prose regularly prefers a possessive genitive with it: proprium populī Rōmānī, “characteristic of the Roman people.”

Fitness and usefulness

Both datives identify groups toward whom the qualities are directed. Perīculōsus does not belong to a memorized short list so much as permit a reference/affected-person reading; this shows how adjective government shades into the broader dative of reference.

This attributed (formal) philosophical example is reproduced in its edited form. Nātūrae identifies the standard or end to which something is fitted.

Here idōneum is accusative because it agrees with direct-object locum; castrīs remains dative. An adjective does not have to be a predicate with sum in order to govern its case.

Friendliness, hostility, and response

This is standard (formal) prose. Nōbīs is not a dative of possession—Latin is not saying “we have tribunes”—because amīcī supplies the relational predicate.

The coordinated datives point in opposite directions. English needs two different adjectives and prepositional habits; Latin uses the same case relation after both.

In hoc onus mihi molestum est, “this burden is troublesome to me,” molestus lexically expresses an unwelcome effect on someone, so mihi is naturally analyzed as its complement. The meaning also resembles disadvantage. Grammar labels overlap, but the immediate dependence on the adjective is the most useful parsing fact.

Nearness, likeness, and equality

Flūminī is dative after propinqua. Ab urbe is an ablative phrase with remōta under separation; the composed sentence deliberately shows that English “to/from” maps onto distinct Latin analyses.

The two things compared are expressed with dative illī. Eadem is nominative feminine because it agrees with imāgō; it does not govern another dative here.

In labor tuus meō pār est, “your effort is equal to mine,” meō is dative masculine singular with an understood labōrī. Latin can omit a repeated noun while preserving its case in the adjective that stands for it.

Competing constructions you must learn

Dative person, ad + accusative purpose

Adjectives of fitness and usefulness regularly take a dative of a person, but often use ad + accusative for an intended purpose or activity.

Mīlitī is the person served by the quality. Ad proelium states the end for which the sword is fitted. A dative of a thing is also possible in established combinations, so this is a preferred semantic division rather than a ban on every alternative.

Dative or genitive with relationship and likeness

Adjectives of likeness, nearness, belonging, and relationship often compete with a possessive genitive. The distinction is clearest when an adjective is shifting toward a noun:

The distribution of similis is genuinely irregular by author and period. Early writers commonly use the genitive; Cicero generally uses the genitive of persons and either genitive or dative of things. Personal pronouns normally appear as meī, tuī, nostrī, and vestrī with similis. There is no single semantic slogan that replaces attention to idiom.

Adjectives of attitude may instead take in or ergā + accusative, especially when the direction of conduct is emphasized: cōmis in uxōrem, “kind toward his wife”; benignus ergā amīcōs, “kind toward friends.” These alternatives are standard Classical prose, not errors.

Parsing sequence and register

When a possible dative stands near an adjective, proceed in this order: identify the adjective’s agreement; decide whether its lexical meaning opens a “to/for” relation; check recognized alternatives; then test broader readings such as reference or advantage. Do not choose the case from proximity on the page.

Adjective-governed datives are normal across Classical registers. Political and philosophical prose frequently uses them in (formal) evaluation; dialogue uses mihi molestum, tibi grātum, and similar personal reactions without sounding elevated. The dative with īdem “the same as” is chiefly (literary) or, in colloquial use, (informal); polished prose normally uses atque/ac or a relative clause. Later Latin expands and redistributes several prepositional alternatives, so Classical composition should follow authorial collocations rather than later habits.

Common Mistakes

1. Using an accusative because English has no visible preposition

2. Making the adjective agree with its dative complement

3. Translating every English “for” with ad

4. Calquing English “similar to” with a preposition

Key Takeaways

Adjectives of fitness, usefulness, attitude, nearness, likeness, and related meanings can direct their quality toward a dative complement. The adjective agrees with the noun it describes, not with that complement. Learn the competing frames honestly: dative people versus ad + accusative purposes, dative versus possessive genitive with relational adjectives, and in/ergā with attitudes. English prepositions are clues to meaning, never reliable case rules.