Miles hostem gladio caedit.

Because miles is in the nominative case, which is the case normally used for the subject in Latin.

In this sentence:

• miles = nominative singular, the soldier
• hostem = accusative singular, the enemy
• caedit = he/she/it strikes/kills/cuts down

So miles is the one doing the action.

The ending -em shows that hostem is accusative singular. The accusative case is commonly used for the direct object, the person or thing receiving the action.

So in Miles hostem gladio caedit, the soldier is acting on the enemy, which is why Latin uses hostem, not hostis.

A learner often meets this noun in the dictionary as:

• hostis, hostis = enemy

But in the sentence, it changes form to hostem because of its job in the sentence.

Here gladio is an ablative of means or instrument. It answers the question with what?

So:

• gladio = with a sword / by means of a sword

Latin often uses the ablative without a preposition when it means by, with, or by means of something.

That is why Latin says gladio, not something like a separate word for with.

Caedit is a verb, specifically:

• 3rd person singular
• present tense
• active voice
• indicative mood

That means it means he/she/it strikes, cuts down, or kills, depending on context.

The ending -t is the important clue: it tells you the subject is he, she, or it rather than I, you, or they.

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

So:

• miles can mean a soldier or the soldier
• hostem can mean an enemy or the enemy
• gladio can mean with a sword or with the sword

You decide which English article fits best from the context.

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

So all of these could mean basically the same thing:

• Miles hostem gladio caedit
• Hostem miles gladio caedit
• Gladio miles hostem caedit

The endings still show:

• miles = subject
• hostem = direct object
• gladio = instrument

That said, word order in Latin can still affect emphasis or style. The basic meaning stays the same, but a different order may highlight a different word.

Because the verb ending already includes that information.

In caedit, the ending -t tells you the verb is 3rd person singular, so Latin already tells you he/she/it strikes.

Since miles is present, you know who that he is: the soldier.

Latin often leaves subject pronouns out unless they are needed for emphasis or contrast.

Miles is a 3rd-declension noun.

Its dictionary form is:

• miles, militis = soldier

That means:

• nominative singular: miles
• genitive singular: militis

Many 3rd-declension nouns are less predictable than 1st- and 2nd-declension nouns, so learners usually memorize both the nominative and genitive forms.

Even though miles ends in -es, here it is singular, not plural.

You know from both the noun form and the verb.

First, caedit is 3rd person singular, so the subject should be singular: he/she/it strikes.

Second, miles is the nominative singular form of the noun. The nominative plural would be:

• milites = soldiers

So:

• miles = soldier
• milites = soldiers

Yes. The ablative here can be translated in a few closely related ways, such as:

• with a sword
• by means of a sword
• using a sword

These are all natural ways to express the same basic Latin idea: the sword is the instrument used in the action.

They are:

• miles, militis = soldier
• hostis, hostis = enemy
• gladius, gladii = sword
• caedo, caedere, cecidi, caesum = strike, cut down, kill

Looking at dictionary forms helps you see where the sentence forms come from:

• miles stays miles
• hostis becomes hostem
• gladius becomes gladio
• caedo becomes caedit

A full parsing would look like this:

• miles: noun, nominative singular, masculine, 3rd declension
• hostem: noun, accusative singular, masculine, 3rd declension
• gladio: noun, ablative singular, masculine, 2nd declension
• caedit: verb, 3rd person singular present active indicative

This is a very useful habit in Latin: identify each word’s case or verb form, and the sentence structure becomes much clearer.