Dux signum dat, et milites ex castris procedunt.

Dux is the subject of dat, so it is in the nominative singular. Its dictionary form is also dux, so it looks unchanged here.

This noun belongs to the 3rd declension:

• nominative singular: dux
• genitive singular: ducis

A learner may expect the subject to come first in English-style order, and here it does: dux = the leader/general is the one doing the action.

Latin has no definite article and no indefinite article. That means there is no separate word for the or a/an.

So:

• dux can mean the leader/general or a leader/general
• milites can mean the soldiers or soldiers

You decide from the context which English wording sounds best.

Signum is the direct object of dat, so it is in the accusative singular.

This happens to look the same as its nominative singular because it is a 2nd-declension neuter noun:

• nominative singular: signum
• accusative singular: signum

A very important neuter pattern in Latin is:

• nominative singular = accusative singular
• nominative plural = accusative plural

Yes. Literally, signum dat means gives a signal.

In military or narrative Latin, signum dare is a very common expression meaning:

• to give the signal
• to give the order to begin
• sometimes more generally to signal

So this is not just any random giving. It is a standard phrase.

Because the sentence is talking about soldiers as a group, and milites is the nominative plural of miles.

Its forms are:

• singular: miles = soldier
• plural: milites = soldiers

Here milites is the subject of procedunt, so both the noun and the verb are plural.

Because its subject, milites, is plural.

Latin verbs agree with their subject in person and number:

• procedit = he/she/it goes forward
• procedunt = they go forward

Since milites means soldiers, the verb must be 3rd person plural: procedunt.

Procedunt comes from procedere, which basically means:

• to go forward
• to advance
• to move out

In this military context, it suggests the soldiers are moving out from the camp or advancing. It is a present-tense form, 3rd person plural.

The preposition ex means out of or from, and it takes the ablative case.

So:

• ex
  • ablative

Here castris is ablative, so ex castris means out of the camp or from the camp.

This is a very common Latin pattern:

• ex urbe = out of the city
• ex provincia = from the province
• ex castris = out of the camp

Because castra is one of those Latin nouns that is usually used in the plural even when it refers to one camp.

Its common forms are:

• nominative/accusative plural: castra
• ablative plural: castris

So ex castris literally looks like out of the camps, but idiomatically it means out of the camp.

This is something learners simply have to get used to: some Latin nouns are plural in form but singular in meaning in English.

Yes. Latin word order is more flexible than English word order because the endings show each word’s job in the sentence.

This sentence uses a fairly clear and straightforward order:

• dux = subject
• signum = object
• dat = verb
• milites = subject
• ex castris = prepositional phrase
• procedunt = verb

But Latin could rearrange the words for emphasis, for example:

• Signum dux dat
• Milites et ex castris procedunt
• Ex castris milites procedunt

The basic meaning would stay the same, though emphasis might shift.

Et means and. It connects the two parts of the sentence:

• Dux signum dat
• milites ex castris procedunt

So the sentence presents two related actions:

1. the leader gives the signal
2. the soldiers move out

It is the ordinary Latin word for and, and it is extremely common.

Yes. Both are present tense:

• dat = he/she gives
• procedunt = they go forward / advance

In Latin storytelling, the present tense is often used vividly to describe events as if they are happening right now. In grammar, this is often called the historical present when used in narrative about past events.

So even if the wider story is about past events, Latin may still use present forms like these for vividness.

You know mainly from the case ending and the verb.

• milites is nominative plural here, so it can be the subject
• procedunt is a plural verb, matching milites

Also, procedere does not normally take a direct object in this kind of sentence. So milites naturally makes sense as the ones advancing, not as something being acted upon.

It can mean several related things depending on context:

• leader
• commander
• general

In military Latin, dux often means a military leader or commander. English translations vary depending on the passage and how formal or specific the translator wants to be.

So if the meaning has already been given to you, that chosen English word is probably just the best fit for that context.