The impersonal verbs interest and rēfert mean “it matters,” “it concerns,” or “it is in someone’s interest.” Interest normally identifies the affected person with a genitive: cīvitātis interest, “it is in the state’s interest.” Personal pronouns with either verb, however, use the exceptional fixed forms meā, tuā, suā, nostrā, and vestrā; in Classical prose these possessive forms are also the normal way to name a person with rēfert, which only exceptionally takes a noun or demonstrative genitive. This is a genuine irregularity, not a pattern that can be predicted from English.
The construction at a glance
Both verbs are normally third-person singular and impersonal in this sense. The thing that matters is supplied by a neuter pronoun, an infinitive construction, an indirect question, or another substantive clause.
| Function | Classical expression | Example | Register |
|---|---|---|---|
| Person/group affected, noun | genitive | cīvitātis interest | ordinary and (formal) prose |
| Person affected, 1st/2nd/reflexive pronoun | possessive adjective, ablative feminine singular | meā, tuā, suā, nostrā, vestrā interest | standard Classical idiom |
| Person affected, demonstrative/third-person reference | genitive | eius, illōrum interest | ordinary Classical prose |
| Degree of concern | genitive of value, adverb, or adverbial accusative | magnī; vehementer; multum interest | ordinary Classical prose |
| Matter in respect of which | ad
| ad honōrem interest | especially (formal) prose |
Cīvitātis interest lēgēs servārī.
It is in the state’s interest that the laws be observed.
Cīvitātis names the interested party. The accusative-and-infinitive clause lēgēs servārī supplies what is advantageous. English makes “the state” the object of “for”; Latin makes it genitive because that is the construction licensed by impersonal interest.
Omnium interest pācem retinēre.
It is in everyone’s interest to preserve peace.
The understood subject of retinēre is generic. When a different explicit subject is needed, Latin can use an accusative-and-infinitive clause.
Caesaris intererat mīlitēs ante noctem advenīre.
It was in Caesar’s interest for the soldiers to arrive before nightfall.
The exceptional personal-pronoun forms
Instead of expected meī, tuī, suī, nostrī, or vestrī, Classical Latin uses forms that look like the ablative feminine singular of possessive adjectives:
| Owner | Required form | Meaning |
|---|---|---|
| I | meā | it concerns me / it is in my interest |
| you, singular | tuā | it concerns you |
| reflexive third person | suā | it concerns himself/herself/themselves |
| we | nostrā | it concerns us |
| you, plural | vestrā | it concerns you all |
The feminine ablative is fossilized; no expressed feminine noun needs to be supplied in ordinary analysis, and the form does not agree with the speaker’s gender. A man and a woman both say meā interest. The historical explanation of the construction has been disputed, so memorizing the five forms is more honest than inventing a transparent ellipsis.
Meā interest tē salvum advenīre.
It matters to me that you arrive safely.
Nostrā multum interest quandō proficīscāmur.
It matters greatly to us when we set out.
The second sentence uses an indirect question, so proficīscāmur is subjunctive. Multum is an adverbial accusative measuring the degree of concern; it does not agree with nostrā.
Quid tuā id rēfert?
What difference does that make to you?
Here id is the thing at issue, tuā identifies the affected person, and interrogative quid asks the degree or nature of the difference. The idiomatic English word order gives no clue to the Latin cases.
Suā versus eius
Suā is reflexive: in reported thought or speech it can refer back to the relevant third-person subject. Eius is the non-reflexive genitive “of him/her.”
Caesar dīxit suā interesse mīlitēs parātōs esse.
Caesar said that it was in his own interest for the soldiers to be ready.
Caesar dīxit eius interesse mīlitēs parātōs esse.
Caesar said that it was in someone else’s interest for the soldiers to be ready.
The surface English “his” is ambiguous; Latin distinguishes indirect reflexive suā from non-reflexive eius. The broader system is explained on the reflexive possessive suus page.
Interest and rēfert are not perfectly interchangeable
Both verbs share the meaning “matter, concern,” but their Classical distributions differ. Interest freely takes genitives of nouns and groups: Caesaris, cīvitātis, omnium. In Classical prose rēfert overwhelmingly favors the possessive forms meā, tuā, suā, nostrā, and vestrā; a noun genitive with rēfert is exceptional. For reliable Classical composition, write cīvitātis interest but meā rēfert.
Meā nōn rēfert utrum māne an vesperī veniās.
It makes no difference to me whether you come in the morning or in the evening.
The paired indirect question utrum … an supplies the alternatives that do or do not matter.
Rēfert in this impersonal idiom should also be kept distinct from the ordinary personal uses of referō “bring back, report.” Similar spelling is not a license to give every use the same syntax.
Saying how much it matters
The degree can be expressed in three ways:
- a genitive of value, including magnī, permagnī, parvī, maximī, plūrimī, minimī, tantī, quantī, tantīdem, plūris, and minōris;
- an adverb: vehementer, maximē;
- an adverbial accusative: multum, nihil.
Meā magnī interest tē huic colloquiō adesse.
It is very important to me that you attend this meeting.
Illud parvī rēfert; hoc autem vehementer interest.
That matters little, but this is extremely important.
In meā magnī interest, meā identifies the affected person and magnī gives the degree. They are not two competing ways to say the same thing. The value genitives receive fuller treatment on the genitive of value and price page.
The matter “with respect to which”: ad + accusative
An ad phrase can name the interest, goal, or topic with respect to which something matters. It does not replace the genitive or meā-type form for the person affected.
Magnī ad honōrem nostrum interest hanc rem celeriter cōnficī.
It is very important for our reputation that this matter be finished quickly.
Ad honōrem nostrum means “with respect to our reputation.” Compare nostrā interest, “it is in our interest.” English may translate both with “for us,” but Latin keeps reference and interested person structurally distinct.
Very rarely, especially in (informal) comedy, ad + accusative can name the person: quid id ad mē rēfert? “what difference does that make to me?” A dative with rēfert is also rare and nonstandard by the norms of polished Classical prose. Recognize these variants; do not use them as the default model.
Quid id ad me aut ad meam rem refert?
What difference does that make to me or to my interests? (Plautus, Persa 513)
The Plautine question is (informal) and (archaic) relative to later Classical prose and is reproduced here as an attributed text rather than silently normalized.
Common Mistakes
1. Using the dative for the person affected
❌ Mihi interest tē adesse.
Nonstandard as the default Classical construction—the English phrase “to me” has triggered a dative.
✅ Meā interest tē adesse.
It matters to me that you are present.
2. Using a personal-pronoun genitive
❌ Meī rēfert quid faciās.
Incorrect in the standard idiom—personal pronouns use the fixed possessive form.
✅ Meā rēfert quid faciās.
It matters to me what you do.
3. Making the fixed possessive agree with a male speaker
❌ Meō interest quandō veniās.
Incorrect—meā is fixed feminine ablative singular and does not agree with the speaker.
✅ Meā interest quandō veniās.
It matters to me when you come.
4. Putting the interested party in the accusative
❌ Senātum interest foedus servārī.
Incorrect—the senate as interested party is not the direct object of the impersonal verb.
✅ Senātūs interest foedus servārī.
It is in the senate’s interest that the treaty be observed.
Key Takeaways
Use a genitive noun or third-person demonstrative for the affected party with interest: cīvitātis, Caesaris, eius. Replace personal-pronoun genitives with the fixed forms meā, tuā, suā, nostrā, and vestrā; these are also the normal Classical partners of rēfert. A clause states what matters, a genitive/adverb/adverbial accusative can state how much, and ad + accusative can mark the respect in which it matters.
Now practice Latin
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Latin →Related Topics
- Genitive with Verbs of Accusing and CondemningB1 — Build Classical judicial constructions with an accusative defendant and a genitive charge, while distinguishing charge from penalty.
- Genitive of Value and PriceB1 — Use the small Classical set of genitives for indefinite value and contrast them with the ablative used for actual prices.
- Dative of ReferenceB1 — Use the dative to mark the person or sphere with reference to whom a statement holds, without turning that participant into an object.
- Possessives Meus, Tuus, Noster, VesterA1 — How first- and second-person Latin possessive adjectives agree, when they are omitted, and how they mark contrast or viewpoint.
- Reflexive Possessive SuusA1 — Use suus, sua, suum for a possession belonging to the clause subject, and distinguish it from non-reflexive eius, eōrum, and eārum.
- Impersonal VerbsB1 — Parse Latin verbs used only or chiefly in the third-person singular, including obligation, emotion, weather, and impersonal passives.