Post longum bellum victoria civibus grata fuit, sed clades hostium etiam pueros terruit.

Because post is a preposition that takes the accusative when it means after.

So:

• post = after
• bellum = war
• longum = long

Since bellum is the object of the preposition post, it must be accusative:

• nominative: bellum
• accusative: bellum

Here the form happens to look the same, which is very common with neuter nouns. The adjective longum also goes into the accusative to match bellum.

Both word orders are possible in Latin. Latin word order is much freer than English word order because the endings show the grammatical relationships.

So both of these can work:

• post longum bellum
• post bellum longum

The version in the sentence is a very natural Latin order. Often an adjective can come before the noun for emphasis or simply as a normal stylistic choice.

Because grata is agreeing with victoria.

• victoria is feminine singular nominative
• grata must match it in gender, number, and case

So:

• victoria grata = a welcome / pleasing victory

This is an example of a predicate adjective: grata is describing victoria, linked to it by fuit.

Civibus is dative plural, from civis (citizen).

It is not the subject because the subject here is victoria. The word civibus is used with grata in the sense pleasing to or welcome to.

So the pattern is:

• victoria civibus grata fuit
• literally: the victory was pleasing to the citizens

This is a very common Latin construction:

• something + gratus/grata/gratum
  • dative person
    = something is pleasing/welcome to someone

Latin often expresses this idea differently from English.

Instead of saying:

• the citizens liked the victory

Latin prefers:

• the victory was pleasing to the citizens

So the grammatical center of the clause is victoria, not civibus.

This is a good reminder that Latin does not always package ideas the same way English does, even when the meaning is straightforward.

Fuit is the perfect tense of sum, meaning was in the sense of was, at a certain time / turned out to be / was as a completed fact.

Erat is the imperfect, meaning was in a more ongoing or background sense.

So:

• grata fuit = was welcome / proved welcome
• grata erat = was being welcome / was welcome as background description

In a simple narrative sentence like this, fuit is very natural because it presents the victory as a completed fact in the past.

Here clades is singular.

It is a fifth-declension noun:

• nominative singular: clades = disaster, defeat
• genitive singular: cladis

So in this sentence:

• clades hostium = the disaster/defeat of the enemies

A learner often expects a nominative singular to end differently, but fifth-declension nouns often have forms like this.

Because hostium is not the subject.

The subject is clades, which is singular:

• clades ... terruit = the disaster/defeat ... frightened

Hostium is genitive plural, meaning of the enemies.

So the structure is:

• subject: clades
• modifying genitive: hostium
• object: pueros
• verb: territuit? Actually here terruit

Therefore the verb is singular because its subject, clades, is singular.

Hostium is genitive plural of hostis.

It means:

• of the enemies
• or sometimes in context of the enemy

So:

• clades hostium = the defeat/disaster of the enemies

The genitive here shows possession or close relationship. It tells you whose defeat it is.

Because pueros is the direct object of terruit.

• terruit = frightened
• the person or thing frightened goes into the accusative

So:

• clades hostium etiam pueros terruit
• the defeat of the enemies frightened even the boys

The boys are the ones affected by the action, so Latin puts pueros in the accusative.

Because terrere takes a direct object, not a dative object.

Compare:

• terruit pueros = frightened the boys
• not terruit pueris

English sometimes uses different patterns with emotional words, but Latin terrere works like a normal transitive verb: someone frightens someone.

So the frightened people go in the accusative.

Etiam means also, even, or also even, depending on context and emphasis.

Here it most naturally means:

• even

So:

• etiam pueros = even the boys

This suggests that the defeat of the enemies was so striking or terrible that it frightened not only others, but even the boys.

Word placement can affect emphasis. Putting etiam right before pueros naturally links it closely to pueros.

Latin often separates words that belong together. This is normal and very common.

In English we usually keep related words close together:

• the victory was welcome to the citizens

In Latin, because the endings show the relationships, the sentence can be arranged more flexibly:

• victoria civibus grata fuit

Here:

• victoria and grata still clearly belong together because they agree in form
• civibus is placed between them because it fits naturally with grata

This kind of arrangement is one of the main stylistic differences between Latin and English.

Classical Latin has no articles like English the or a/an.

So:

• victoria can mean victory, a victory, or the victory
• civibus can mean to citizens or to the citizens
• pueros can mean boys or the boys

You decide from context what sounds best in English.

The conjunction sed tells you clearly that a new clause is starting.

So the sentence divides like this:

1. Post longum bellum victoria civibus grata fuit
2. sed clades hostium etiam pueros terruit

• sed = but

Each clause has its own main verb:

• fuit
• terruit

That makes the structure easier to see.

Yes, sometimes hostes and its forms can be translated as either the enemy or the enemies, depending on context.

Grammatically, hostium is definitely genitive plural, but in English a plural Latin word may sometimes be rendered by a collective singular:

• of the enemies
• of the enemy

If the meaning has already been given to you, follow that translation, but it is useful to know that both can be possible in English style.

A learner often wants to identify each word fully. Here they are:

• post — preposition meaning after
• longum — from longus, longa, longum, long
• bellum — from bellum, belli n., war
• victoria — from victoria, victoriae f., victory
• civibus — from civis, civis m./f., citizen
• grata — from gratus, grata, gratum, pleasing, welcome
• fuit — from sum, esse, was / has been
• sed — but
• clades — from clades, cladis f., disaster, defeat
• hostium — from hostis, hostis m./f., enemy
• etiam — also, even
• pueros — from puer, pueri m., boy
• terruit — from terreo, terrere, terrui, territus, frightened

Seeing the dictionary forms helps explain the endings and the syntax.