Eodem die soror cum amica concentum parat, quia convivae vespere venturi sunt.

Eodem die means on the same day and gives the time setting right away.

Grammatically, die is ablative singular of dies, and eodem is the ablative singular form of idem (the same), agreeing with die. This is an example of the ablative of time when, which Latin often uses without a preposition:

• eo die = on that day
• eodem die = on the same day

So Latin puts the time phrase first for emphasis or simply because the word order is flexible.

Because eodem has to agree with die.

The noun dies is usually masculine in expressions like this, and here it is:

• die = masculine ablative singular
• therefore eodem must also be masculine ablative singular

Latin adjectives and pronouns must match the noun they describe in gender, number, and case.

Amica is in the ablative singular because the preposition cum meaning with takes the ablative.

So:

• cum amica = with a friend or with her friend

This is the ordinary prepositional use of cum, not the conjunction cum meaning when/since/although.

Because the true subject is only soror.

• soror = sister → singular subject
• cum amica = with a friend → just a prepositional phrase, not part of the subject

So Latin, like English, uses a singular verb:

• soror ... parat = the sister prepares

If both were the subject, Latin would say something like soror et amica parant.

Concentum is the direct object of parat.

• parat = prepares
• what does she prepare? concentum

So concentum is in the accusative singular, because direct objects in Latin normally take the accusative.

Concentus, concentus is a fourth-declension noun. It can mean something like:

• concert
• musical performance
• harmonious singing or music

In this sentence, it most naturally means a concert or a musical event.

Its form here, concentum, is accusative singular.

Quia means because and introduces the reason for the action in the main clause.

So the sentence is structured like this:

• main clause: Eodem die soror cum amica concentum parat
• reason clause: quia convivae vespere venturi sunt

In other words, she is preparing the concert because the guests are going to come in the evening.

Because Latin often uses the ablative of time when without a preposition for expressions of time.

So:

• vespere = in the evening / in the evening time

This is similar to eodem die earlier in the sentence. Latin often says simply:

• nocte = at night
• aestate = in summer
• vespere = in the evening

No in is needed.

Venturi sunt is a very common Latin way to express a future idea.

It is made of:

• venturi = future active participle of venire (about to come, going to come)
• sunt = are

Together, venturi sunt means:

• they are going to come
• they will come
• more literally, they are about to come

This is called the future active periphrastic.

Because it is really a participle + a form of esse.

Latin builds this future expression in two pieces:

• venturi = participle
• sunt = present tense of to be

The participle agrees with the subject, while sunt supplies the finite verb.

So convivae venturi sunt literally means the guests are going-to-come.

Here convivae is nominative plural, because it is the subject of venturi sunt.

The noun is conviva, convivae, a first-declension noun meaning guest.

So:

• singular: conviva
• plural: convivae

Even though it is first declension, it can refer to a man or a woman.

Good question. First declension does not automatically mean feminine natural gender.

Conviva is a common-gender noun: it can refer to male guests, female guests, or a mixed group.

The participle must agree with the actual gender of the people meant, not just the declension pattern. So:

• convivae venturi sunt = the guests are going to come, if the group is masculine or mixed
• convivae venturae sunt = the guests are going to come, if the group is all female

So venturi tells you the guests are being treated as masculine or mixed.

It is very close in meaning, but not exactly the same in feel.

• venient = they will come
• venturi sunt = they are going to come / are about to come

The periphrastic form can sound a little more deliberate or vivid, sometimes suggesting an expected or impending action. In many contexts, though, both can be translated simply as will come.

Latin word order is much more flexible because the endings show each word’s role.

For example:

• soror is clearly the subject
• concentum is clearly the object
• amica is governed by cum
• convivae is clearly the subject of the subordinate clause

Because of that, Latin can arrange words for emphasis, style, or rhythm. This sentence puts:

• eodem die first to set the time
• vespere before venturi sunt to highlight when the guests will come

English depends much more on fixed word order, but Latin depends more on endings.

No, not here.

Here cum is followed by amica in the ablative, so it is clearly the preposition with:

• cum amica = with a friend

If cum meant when, it would introduce a clause with a verb, not just a noun phrase.

There are two clauses, and each has its own verb:

1. Main clause:

   • parat = prepares

2. Subordinate clause introduced by quia:

   • sunt is the finite verb, together with venturi
   • so the full verbal idea is venturi sunt = are going to come

This is useful because learners often first spot parat easily, but in the second clause the future meaning is split between two words.