Si iustitia in iudicio servatur, etiam reus aequum iudicium sperat.

Si means if and introduces a conditional clause.

So:

• Si iustitia in iudicio servatur = If justice is preserved in a trial / in court

In this sentence, si sets up the condition, and the main clause follows:

• etiam reus aequum iudicium sperat = even the defendant hopes for a fair trial/judgment

Servatur is the 3rd person singular present passive indicative of servare.

• servat = he/she/it preserves
• servatur = he/she/it is preserved

Here, iustitia is the subject, so the Latin literally says:

• justice is preserved

Latin uses the passive because the focus is on what happens to justice, not on who preserves it.

Because iustitia is in the nominative singular, and it matches servatur in number:

• iustitia = nominative singular
• servatur = is preserved (3rd person singular)

So iustitia is the thing being described as being preserved.

Because in takes different cases depending on meaning:

• in + ablative = in / on a place or situation
• in + accusative = into / onto motion toward

Here there is no motion. The meaning is in the trial or in court, so Latin uses the ablative:

• in iudicio

That is why iudicio is ablative singular.

Iudicio is ablative singular of iudicium.

Iudicium can mean things like:

• judgment
• trial
• court proceeding
• sometimes decision

In this sentence, in iudicio most naturally means in the trial or in court.

No, because reus is the subject of sperat.

• reus = the defendant / accused person
• sperat = hopes

So the structure is:

• the defendant hopes

Even though English learners may associate defendant with being “acted upon,” grammatically here the defendant is the one doing the hoping, so Latin uses the nominative.

Aequum iudicium is accusative singular neuter because it is the direct object of sperat.

• aequum = accusative singular neuter of aequus (fair, just)
• iudicium = accusative singular neuter

Together they mean:

• a fair judgment
• or, depending on context, a fair trial

The adjective and noun match in:

• case
• number
• gender

They are two forms of the same noun, iudicium, but they have different grammatical jobs:

• in iudicio = ablative after in, meaning in the trial / in court
• aequum iudicium = accusative as the object of sperat, meaning a fair judgment/trial

So the difference is not vocabulary, but case and function.

This is a simple or general present condition:

• Si ... servatur, ... sperat
• If justice is preserved..., the defendant hopes...

Both verbs are in the present indicative, which often expresses a straightforward condition: if X happens, Y happens.

It does not suggest unreality or impossibility. It simply states a normal relationship between the two ideas.

Here etiam most naturally emphasizes reus:

• etiam reus = even the defendant

That means the sense is:

• if justice is preserved in court, even the accused person can hope for fairness

So etiam adds emphasis and suggests that the defendant may be the person one might least expect to feel confident.

Yes. In Latin, sperare can take a direct object in the accusative.

So:

• aequum iudicium sperat = he hopes for a fair trial/judgment

English often uses hope for, but Latin can simply use the accusative object without a preposition.

Because Classical Latin has no articles.

So:

• reus can mean the defendant or a defendant
• aequum iudicium can mean a fair trial or the fair judgment, depending on context
• iustitia can mean justice

English must choose an article, but Latin usually leaves that to context.

Latin word order is much more flexible than English word order because the endings show grammatical function.

This sentence places the conditional clause first:

• Si iustitia in iudicio servatur, ...

Then the main clause:

• etiam reus aequum iudicium sperat

That order is natural and clear. It also helps the sentence build logically:

1. state the condition
2. give the result

The placement of etiam right before reus also helps emphasize even the defendant.

All of those can work depending on how idiomatic you want the English to be.

Very literal:

• is preserved

More natural in legal or ethical English:

• is observed
• is upheld

So the Latin idea is that justice is being maintained, respected, or upheld in the judicial process.