Using the Passive Voice - Agent

Now that we have covered all the forms of the passive voice indicative for each conjugation, it is important to take some time to discuss how the passive voice is used and translated in context.

The passive voice construction, in general, is an inversion of the usual active construction. The direct object in an active construction becomes the subject in a passive construction.

Consider the following example, comparing active and passive constructions of the same sentence:

Selene heard the information.
- information is the direct object in the active construction
The information was heard by Selene.
- information is the subject in the passive construction

Agent

In grammar, the term agent is the noun which is performing the action of a verb: the doer. What happened to the agent of the active construction - Selene? In a passive construction, the subject is never the agent. However, the agent can still be expressed: in the above example, we see the agent expressed in English with the prepositional phrase by Selene.

The expression of the agent is handled in Latin in two ways:

Ablative of Agent for people
Ablative of Means for inanimate nouns

Ablative of Agent

For the Ablative of Agent, the preposition by is expressed with the Latin preposition ab (recall that this preposition can be abbreviated a in front of consonants). The agent is placed in the ablative case:

ab/a Selena
- you can use either ab or a in front of the noun Selena

Let's look at an example in Latin using the English example from above. The passive construction will include the ablative of agent:

Active Voice Construction: Selene informationem audiebat. - Selene heard the information.
- To invert, change:
  - informationem (accusative) to informatio (nominative)
  - Selene (nominative) to a Selena (ablative of agent)
  - audiebat (active) to audiebatur (passive)
Passive Voice: Informatio a Selena audiebatur. - The information was heard by Selene.

Ablative of Means

For inanimate nouns (nouns that are not people) we do not use the ablative of agent, since an inanimate object does not have agency, but rather we use the ablative of means. The ablative of means omits (leaves out) the preposition ab/a and simply places the noun in the ablative case:

Active:
- Latin: Venenum Marcellum necavit.
- English: Poison killed Marcellus.
Passive:
- Latin: Marcellus veneno necatus est.
- English: Marcellus was killed with poison.

Let's review a few more examples to see this inversion in practice. Ablative of agent/means are highlighted in bold.

**Active and Passive Construction Comparison**
Latin - Active Sentence	English - Active Translation	Latin - Passive Construction	English - Passive Translation
Servus nuntium ad Liviam portavit.	A slave carried the message to Livia.	Nuntius ad Liviam a servo portatus est.	The message has been carried to Livia by a slave.
Si Pseudolus Maecenatem non invenerit, omnem spem perdet.	If Pseudolus does not find Maecenas, he (Pseudolus) will lose all hope.	Si Maecenas a Pseudolo non inventus erit, omnem spem perdet. Si Pseudolus Maecenatem non invenerit, omnis spes ab eo perdetur.	If Maecenas is not found by Pseudolus, he (Pseudolus) will lose all hope. If Pseudolus does not find Maecenas, all hope will be lost by him (Pseudolus).
Aqua vulnus altum indicaverat.	The water had revealed a deep wound.	Vulnus altum aqua indicatum erat. *aqua is ablative of means	The deep wound had been revealed with the water.
Selene Pseudolo veritatem dicet.	Selene will tell Pseudolus the truth.	Pseudolus veritatem a Selena dicetur. Veritas Pseudolo a Selena dicetur.	Pseudolus will be told the truth by Selene. The truth will be told to Pseudolus by Selene.

Nota Bene

In the final example, either the direct object (veritatem) or the indirect object (Pseudolo) can be made the subject of the passive construction. In either case, the subject (Selene) is still made the ablative of agent, with the other form retaining its original role.