The accusative-infinitive is like a ‘formula’ i.e. certain consistent changes are made to create an indirect statement from a direct one.
Direct statement: Caesar urbī appropinquat. │ Caesar is approaching the city.
To turn it into an indirect statement, two changes are made:
Nūntiī clāmant ¦ [1] Caesarem urbī [2] appropinquāre.
The messengers shout ¦ that [1] Caesar [2] is approaching the city.
[1] The subject of the indirect statement is in the accusative case; in grammar this is known as the subject accusative
[2] The verb of the indirect statement becomes an infinitive.
That’s why the construction is referred to as an accusative-infinitive.
There is no word for a ‘that’ conjunction introducing the indirect statement.
Examples:
[i] Duo fūrēs in apodyteriō sunt. │ Two thieves are in the changing room.
> Mārcus dīcit ¦ [1] duōs fūrēs [direct object: accusative] [2] esse [infinitive] in apodytēriō.
[literally: Marcus says ¦ [1] two thieves [2] to be in the changing room.]
> Marcus says ¦ that two thieves are in the changing room.
[ii] Is venit. │ He is coming.
> Sciō ¦ [1] eum [accusative] [2] venīre [infinitive]
[literally: I know ¦ [1] him [2] to be coming]
> I know ¦ that he is coming.
[iii] Discipulī student. │ The pupils are studying.
Magister dīcit ¦ [1] discipulōs [accusative] [2] studēre [infinitive]
[literally: The teacher says ¦ [1] the pupils [2] to be studying]
> The teacher says ¦ that the pupils are studying.
At first sight, the accusative-infinitive seems completely alien but, when you take a second look, there are some limited examples in English, restricted largely to expression of opinion, which give you an idea as to how it is put together.
I knew that [1] he [2] was an honest man.
= I knew [1] him [direct object] [2] to be [infinitive] an honest man
I believe that [1] the story [2] is true.
= I believe [1] the story [direct object] [2] to be true [infinitive].
We believe that [1] these truths [2] are self-evident.
= We hold [1] these truths [direct object] ¦ [2] to be [infinitive] self-evident.
Whereas in English, its use is limited and, at times, can sound rather stilted, it is that construction which is the way in which an indirect statement is always expressed in Latin.
