Pater dicit lupum saevum prope villam esse.

Because after dicit here, Latin uses an indirect statement construction: accusative + infinitive.

So instead of saying:

• Pater dicit quod lupus saevus prope villam est
  “Father says that a fierce wolf is near the house”

Classical Latin normally says:

• Pater dicit lupum saevum prope villam esse

In this pattern:

• lupum = the subject of the reported statement, but in the accusative
• esse = the verb of the reported statement, in the infinitive

So lupum is not the direct object of dicit in the English sense. It is the subject of esse inside the indirect statement.

For the same reason: this is an indirect statement.

In direct speech, you would have:

• Lupus saevus prope villam est
  “A fierce wolf is near the house.”

When that statement is reported after a verb like dicit, Latin changes:

• the subject to the accusative
• the finite verb to the infinitive

So:

• lupus → lupum
• est → esse

That gives:

• lupum saevum prope villam esse

Because Latin usually does not use a conjunction like English that in this kind of sentence.

English says:

• “Father says that a fierce wolf is near the house.”

Latin usually prefers the accusative-and-infinitive construction instead:

• Pater dicit lupum saevum prope villam esse.

So the idea of English that is built into the grammar of lupum ... esse, rather than being expressed by a separate word.

Because saevum is describing lupum, so it must agree with it in:

• gender: masculine
• number: singular
• case: accusative

Since lupum is masculine singular accusative, the adjective must also be masculine singular accusative:

• lupum saevum = “a fierce wolf”

If the noun were nominative, then the adjective would also be nominative:

• lupus saevus

Villam is accusative singular because it follows the preposition prope.

Prope means near and commonly takes the accusative in Latin:

• prope villam = “near the house / farmhouse”

So even though English uses no obvious case ending after near, Latin does.

Here prope means near or close to.

So:

• prope villam = “near the house,” “near the farmhouse,” or “near the villa”

A learner should note that villa in Latin often means a country house, farmhouse, or estate, not necessarily a modern luxury villa.

The subject of the main sentence is Pater.

• Pater = “father”
• dicit = “says”

So Pater dicit means “Father says.”

Then everything after that — lupum saevum prope villam esse — is the content of what he says.

So there are really two layers:

1. Main statement: Pater dicit = “Father says”
2. Reported statement: lupum saevum prope villam esse = “that a fierce wolf is near the house”

Not in the ordinary English-style sense.

It may look tempting to call lupum the direct object of dicit, because it is accusative, but more precisely lupum saevum esse is an indirect statement, and lupum is the subject of the infinitive esse.

So the structure is better understood as:

• dicit = “says”
• lupum saevum prope villam esse = “that a fierce wolf is near the house”

This is an important Latin pattern, and it is better to recognize the whole clause than to analyze lupum as a simple standalone object.

Latin word order is much more flexible than English word order.

Placing esse at the end is very normal in Latin, especially in an indirect statement. The sentence groups naturally like this:

• Pater dicit | lupum saevum prope villam esse

Latin often likes to place the verb, especially an infinitive like esse, at the end of its clause.

So while English strongly prefers:

• “Father says a fierce wolf is near the house,”

Latin comfortably says:

• Pater dicit lupum saevum prope villam esse.

Yes, often they could.

Because Latin uses case endings to show grammatical roles, word order can vary more than in English. For example, these would still express essentially the same basic meaning:

• Pater lupum saevum prope villam esse dicit.
• Lupum saevum pater prope villam esse dicit.

However, different orders can slightly change emphasis or style.

The textbook order you have here is clear and natural:

• main verb first: Pater dicit
• then the indirect statement: lupum saevum prope villam esse

Because Latin has no articles.

So:

• lupus / lupum can mean wolf, a wolf, or the wolf
• villa / villam can mean house/farmhouse, a house, or the house

You decide from context which English article sounds best.

That is why lupum saevum prope villam esse could be translated as:

• “that a fierce wolf is near the house”
• “that the fierce wolf is near the house”
• “that a fierce wolf is near a house”

Usually the context tells you which is most natural.

Yes. Dicit is present tense, third person singular, from dicere.

So it means:

• he says
• she says
• or here, with Pater, father says

Because the main verb is present, the sentence means something like:

• “Father says that a fierce wolf is near the house.”

The dictionary forms are:

• Pater → pater, patris = father
• dicit → dico, dicere, dixi, dictum = say, tell
• lupum → lupus, -i = wolf
• saevum → saevus, -a, -um = fierce, savage
• prope = near
• villam → villa, -ae = farmhouse, house, estate
• esse → sum, esse, fui = to be

Seeing the dictionary forms can help you understand why the endings change in the sentence.