Ablative of Agent indicates the person or people who perform the action of a passive voice verb form (verb, infinitive, or participle).

Latin to English - The preposition ā or ab followed by A PERSON OR PEOPLE in the ablative case indicates agent. It translates as "by A PERSON OR PEOPLE."

English to Latin - To express "by A PERSON OR PEOPLE" in Latin, use the preposition ā or ab, and put A PERSON OR PEOPLE in the ablative case.

Helpful Hints:

Expectation is one of the most powerful tools of able translators. The more you develop a sense of expectation, the more your translations will be fast and right.

When you have a passive voice verb form (a verb ending with -r, -ris, -tur; -mur, -mini, -ntur a two-part verb an infinitive ending with -i a participle coming from the fourth part of the dictionary entry of a verb), you can expect to see either an Ablative of Means (if the action of the verb form is performed by a thing) or an Ablative of Agent (if the action of the verb form is performed by a person or people). You do not have to get one of the ablative constructions, but it happens frequently enough to be useful.

When you have the preposition ā or ab followed by a person or people, you can expect to see some kind of passive voice verb form (a verb ending with -r, -ris, -tur; -mur, -mini, -ntur a two-part verb an infinitive ending with -i a participle coming from the fourth part of the dictionary entry of a verb). You can also expect that ā or ab will be translated as "by." N.B.: If you do NOT, in fact, encounter a passive voice verb form, then the prepositional phrase CANNOT be ablative of agent. It is likely to be Ablative of Place from Which (if the action verb in the active voice is a Verb of Motion). It can also be an Ablative of Separation (if the concept of freeing or releasing is present).