Iudex dicit ream innocentem esse.

Because it is the subject of the infinitive esse inside an indirect statement.

After verbs like dicit (says), Latin often does not use a that-clause the way English does. Instead, it uses:

accusative + infinitive

So in Iudex dicit ream innocentem esse, the main verb is dicit, and the reported statement is ream innocentem esse.

Within that reported statement, ream is the person being described as innocent, so it becomes the accusative subject of esse.

Because it agrees with ream.

In ream innocentem esse, innocentem is a predicate adjective describing ream, so it must match it in:

• case: accusative
• number: singular
• gender: feminine

So:

• ream = accusative singular feminine
• innocentem = accusative singular feminine

Latin is saying, literally, the judge says the defendant to be innocent, where innocentem describes ream.

This is the very common Latin construction called the accusative-and-infinitive construction, often shortened to ACI.

Pattern:

• a verb of saying, thinking, knowing, hearing, etc.
• then an accusative
• then an infinitive

Here:

• Iudex = the judge
• dicit = says
• ream = the female defendant
• innocentem = innocent
• esse = to be

So the structure is:

• Main clause: Iudex dicit = The judge says
• Indirect statement: ream innocentem esse = that the female defendant is innocent

Latin uses ream innocentem esse where English uses that the defendant is innocent.

Because in an indirect statement Latin normally uses an infinitive, not a finite verb.

So instead of something like:

• The judge says that the defendant is innocent

Latin says, more literally:

• The judge says the defendant to be innocent

That is why you get esse (to be) rather than est (is).

Because Latin word order is much freer than English word order, and infinitives often come at the end of an indirect statement.

So ream innocentem esse is a very natural order in Latin.

The ending position helps gather the whole reported statement together. But Latin could move words around for emphasis much more easily than English can, because the grammar is shown by the word endings.

Iudex is nominative singular.

It is the subject of the main verb dicit.

So:

• iudex = the judge
• dicit = says

Together: The judge says ...

This is separate from ream innocentem esse, which is the content of what the judge says.

No. Here rea means female defendant or female accused person.

This is an important point, because reus, rea, reum can function as a noun meaning:

• defendant
• accused person

It does not automatically mean the person is actually guilty.

So ream innocentem esse is not contradictory. It does not mean the guilty woman is innocent. It means the female defendant is innocent.

Because ream is feminine singular, so the person being talked about is a female defendant.

That also forces innocentem to be feminine singular to agree with it.

If the defendant were male, Latin would say:

Iudex dicit reum innocentem esse.

Because of the grammar.

• iudex is nominative singular
• ream is accusative singular feminine
• innocentem is accusative singular feminine

Since innocentem matches ream in case, number, and gender, it describes ream, not iudex.

Also, in the ACI construction, the adjective inside the indirect statement normally agrees with the accusative subject of that infinitive.

Dicit is present tense, third person singular:

• he says
• she says
• the judge says

So Iudex dicit ream innocentem esse most naturally means:

• The judge says that the female defendant is innocent.

Depending on context, English might also say:

• The judge is saying that the female defendant is innocent.

But the basic Latin tense is present.

Yes. Esse is the present infinitive of sum.

In an indirect statement, the tense of the infinitive is usually relative to the main verb:

• present infinitive = action/state happening at the same time as the main verb
• perfect infinitive = action/state earlier than the main verb
• future infinitive = action/state later than the main verb

So dicit ... esse suggests:

• the judge says that she is innocent

If Latin wanted to say the judge says that she was innocent, it would normally use a perfect infinitive instead.

Sometimes later Latin, and occasionally other styles, can use quod with a finite verb. But in standard Classical Latin, after a verb like dicit, the normal construction is the accusative-and-infinitive.

So for a learner, this sentence is a textbook example of the normal Classical pattern:

dicit + accusative + infinitive

Only partly.

A very literal version is:

The judge says the female defendant to be innocent.

That helps show the Latin grammar, especially the ACI construction. But normal English usually says:

The judge says that the female defendant is innocent.

So for understanding Latin structure, the literal version is useful; for natural English, the that-clause translation is better.