Dux proelium committit.

• dux = a noun, nominative singular, meaning leader or commander
• proelium = a noun, accusative singular here, meaning battle
• committit = a verb, 3rd person singular present active indicative, from committere

So the sentence is built as:

• subject: dux
• direct object: proelium
• verb: committit

In very plain grammatical terms: The commander engages the battle / The commander joins battle.

Because dux is in the nominative case, which is the case normally used for the subject of a sentence in Latin.

Its dictionary form is dux, ducis. This is a third-declension noun. In this sentence, the form dux is nominative singular, so it means the leader/commander as the one doing the action.

Also, the verb committit is singular, so it matches a singular subject like dux.

Here proelium is the direct object, so it is functioning as accusative singular.

A useful thing to notice is that proelium is a neuter second-declension noun. For many neuter nouns in Latin, the nominative and accusative forms are the same. So proelium can be either nominative singular or accusative singular in form.

How do we know it is accusative here?

• from the meaning of the sentence
• from the structure of the clause
• from the common Latin expression proelium committere, which means to join battle or to engage in battle

So even though the form looks the same, its job in this sentence is accusative.

Committit is the 3rd person singular present active indicative of committere.

That means it can be translated as:

• he commits
• she commits
• it commits

But in this military context, committere proelium is an idiomatic expression meaning something like:

• to join battle
• to engage the enemy
• to begin the fight

So committit here is not the everyday English idea of commit in the moral sense. It has a special military meaning because of the object proelium.

Because Latin often has set expressions whose natural English translation is not word-for-word.

The phrase proelium committere is a standard military expression. Literally, it looks like to commit a battle, but natural English would be:

• to join battle
• to engage in battle
• to give battle

So the translation depends on the phrase as a whole, not just on the isolated verb.

Because Latin does not have articles like English the and a/an.

So:

• dux can mean a leader, the leader, a commander, or the commander
• proelium can mean a battle or the battle

Which one is best depends on the context. In a short classroom sentence, English often adds the because it sounds more natural: The commander joins battle.

Because the verb ending already tells you the subject is he/she/it.

In committit, the ending -it shows 3rd person singular. So Latin does not need a separate subject pronoun unless it wants extra emphasis or contrast.

That means:

• committit by itself could mean he/she/it engages
• adding dux makes clear who is doing it: the commander

Latin often leaves subject pronouns unstated unless they are needed.

Yes, but not in the same rigid way as in English.

Latin uses case endings more than word order to show grammatical function. So the core meaning would stay the same in several different orders, such as:

• Dux proelium committit
• Proelium dux committit
• Dux committit proelium

However, the word order can change the emphasis.

In Dux proelium committit:

• dux comes first, so the commander is a natural point of focus
• committit comes last, which is very common in Latin prose

So word order in Latin is flexible, but not meaningless.

• dux, ducis is a third-declension noun
• proelium, proelii is a second-declension neuter noun

That helps explain their forms:

• dux = nominative singular
• proelium = nominative/accusative singular neuter

So this sentence gives you one common third-declension noun and one common second-declension neuter noun.

Committere belongs to the third conjugation.

Its main parts are:

• committo
• committere
• commisi
• commissum

The form committit is built from that verb and means he/she/it commits, or in this context, he/she/it joins battle.

Yes. Dux basically means leader or guide, and it can be used in different contexts.

Depending on context, it might mean:

• leader
• commander
• general
• guide

But with proelium committit, the military sense is clearly the natural one, so commander or general is the best fit.

In a classical-style pronunciation, approximately:

• dux = dooks
• proelium = roughly PRO-eh-lee-um
• committit = kom-MIT-tit

A few helpful points:

• x sounds like ks
• u is pronounced like oo
• double tt is pronounced more clearly than a single t
• the stress in committit falls on mit

So the whole sentence is roughly:

dooks PRO-eh-lee-um kom-MIT-tit

In form, yes: proelium could be nominative singular, because neuter nominative and accusative are identical.

But in this sentence, it is understood as the object because:

• dux is a very natural subject
• committere proelium is a known expression
• the meaning of the sentence strongly points that way

So this is a good example of how Latin readers use both forms and context together.