Dux prudens ordinem tenet et milites ante proelium instruit.

The sentence has:

• dux prudens = the subject, a prudent/wise leader
• ordinem tenet = first verb phrase, keeps order
• et = and
• milites ante proelium instruit = second verb phrase, trains / arranges the soldiers before the battle

So the core pattern is:

Subject + verb + object + and + object + phrase + verb

More literally, Latin gives:

The prudent leader keeps order and instructs the soldiers before battle.

Dux is in the nominative singular, which is the case normally used for the subject of a sentence.

Its dictionary form is:

• dux, ducis = leader, commander

Here, dux means the leader/commander is the one doing both actions:

• tenet = he/she keeps
• instruit = he/she instructs / arranges

Prudens is an adjective meaning prudent, wise, sensible.

It agrees with dux in:

• case: nominative
• number: singular
• gender: it matches the noun it describes

So dux prudens means:

• the prudent leader
• the wise commander

A learner may expect an adjective ending like -us or -a, but prudens is a third-declension adjective, so its nominative singular form looks different.

Ordinem is the direct object of tenet.

• tenet = holds, keeps, maintains
• What does the leader keep? ordinem

So ordo, ordinis becomes ordinem in the accusative singular.

In this sentence, ordinem tenere means something like:

• to keep order
• to maintain discipline/formation

Literally, it means he holds order, but in better English it usually means:

• he keeps order
• he maintains discipline
• he preserves formation

In a military context, ordo can suggest not just abstract order, but also rank, line, formation, discipline, or organized arrangement.

So this phrase can carry a strong military sense.

Because milites is the direct object of instruit.

• instruit = he instructs / equips / arranges
• Whom does he instruct or arrange? milites = the soldiers

Miles, militis is a third-declension noun, and its accusative plural is milites.

So:

• milites = the soldiers as the object of the verb

Both are:

• present tense
• indicative mood
• active voice
• third person singular

So they mean:

• tenet = he/she keeps
• instruit = he/she instructs / arranges

They are singular because the subject, dux, is singular.

Because the same subject, dux prudens, is understood with both verbs.

So Latin is doing the equivalent of:

• The prudent leader keeps order and instructs the soldiers.

It does not need to repeat dux before the second verb.

This is very normal in both Latin and English.

Ante here is a preposition meaning before, and it takes the accusative case.

So:

• ante = before
• proelium = accusative singular of proelium, battle

Together:

• ante proelium = before the battle

This phrase tells us when the soldiers are instructed.

Because ante, when used as a preposition meaning before, takes the accusative.

So the noun after it must be accusative:

• dictionary form: proelium, proelii = battle
• in the sentence: proelium = accusative singular

This is one of those things that Latin learners simply memorize with prepositions: certain prepositions regularly govern certain cases.

It can mean several related things, depending on context.

From instruo, instruere, it can mean:

• instruct
• equip
• draw up
• arrange
• marshal

So in a military sentence like this, milites ante proelium instruit could suggest:

• he trains the soldiers before the battle
• he prepares the soldiers before the battle
• he draws up the soldiers before the battle

If your provided translation says instructs, that is fine, but the military nuance may be broader than classroom-style teaching.

For practical reading purposes, you should treat prudens as an adjective meaning prudent or wise.

Historically, it is related to a participial form, but in normal Latin learning it functions as a regular adjective.

So in this sentence, the important point is simply:

• prudens describes dux
• it agrees with dux
• it adds the idea wise/prudent

Because Latin has no articles.

So dux can mean:

• a leader
• the leader

and milites can mean:

• soldiers
• the soldiers

You decide which is best from context and from the translation you have been given.

That is why a Latin sentence often looks more bare than an English one.

Yes. Latin word order is fairly flexible because the endings show each word’s role.

For example, these would still mean roughly the same thing:

• Prudens dux ordinem tenet et milites ante proelium instruit.
• Milites ante proelium dux prudens instruit et ordinem tenet.

But word order is not meaningless. It can affect:

• emphasis
• style
• rhythm

The given order is straightforward and natural: first the subject, then one action, then the second action.

Because milites is the accusative plural form of miles, militis.

So:

• miles = soldier (singular)
• milites = soldiers (plural)

That tells you the leader is instructing more than one soldier.

Et is the normal Latin word for and.

It connects the two actions of the same subject:

• ordinem tenet
• milites ante proelium instruit

Latin also has other ways to say and, such as -que, but et is the simplest and most direct choice here.

A useful vocabulary list would be:

• dux, ducis — leader, commander
• prudens, prudentis — prudent, wise
• ordo, ordinis — order, rank, formation
• teneo, tenere — hold, keep, maintain
• et — and
• miles, militis — soldier
• ante — before
• proelium, proelii — battle
• instruo, instruere — instruct, equip, arrange, draw up

This sentence is especially good for practicing:

• subject in the nominative
• direct objects in the accusative
• a preposition with the accusative
• present-tense verbs
• adjective agreement