Nec Lucia nec Marcus hodie ad scholam veniunt.

Nec ... nec means neither ... nor.

So:

• Nec Lucia nec Marcus = neither Lucia nor Marcus

Latin often repeats the negative connector before each item, just as English does in neither Lucia nor Marcus.

You may also see neque ... neque, which means the same thing. In many sentences, nec and neque are interchangeable.

Because together they make a compound subject.

• Lucia = one person
• Marcus = one person
• Lucia and Marcus together = more than one person

So the verb must be 3rd person plural:

• venit = he/she comes
• veniunt = they come

Even though Latin uses neither ... nor, the verb is still plural here because it refers to both people.

They are the subjects of the sentence, so they are in the nominative case.

• Lucia is nominative singular
• Marcus is nominative singular

Latin changes noun endings depending on their role in the sentence. Since Lucia and Marcus are the ones doing the action of coming, they stay in the nominative.

Because Latin usually uses ad + the accusative case to mean to a place.

• ad = to, toward
• scholam = accusative singular of schola

So:

• ad scholam = to school

If you used schola by itself, that would not express motion toward school in normal Latin.

It is accusative because it follows the preposition ad.

Many Latin prepositions require a specific case. Ad takes the accusative.

So:

• schola = nominative/ablative form
• scholam = accusative form

Since the sentence means movement toward school, Latin uses:

• ad scholam = to school

Latin often expresses this idea with a verb of motion plus ad + accusative.

Here:

• veniunt = they come
• ad scholam = to school

Together, that gives they come to school.

English sometimes says simply go to school, but Latin may choose a verb that is best translated as come, depending on the context. The important grammar point is that motion toward a place is shown by ad scholam.

Hodie means today.

It is an adverb, so it modifies the verb:

• veniunt = they come
• hodie veniunt = they come today

It tells when the action happens.

Yes, Latin word order is fairly flexible.

This sentence has:

• Nec Lucia nec Marcus hodie ad scholam veniunt

But Latin could place hodie elsewhere and still mean the same thing, for example:

• Hodie nec Lucia nec Marcus ad scholam veniunt

The choice of position can affect emphasis more than basic meaning. In the given sentence, hodie sits naturally between the subject and the phrase ad scholam.

Latin has no articles.

That means there is no direct equivalent of English the or a/an.

So scholam can mean, depending on context:

• school
• the school
• sometimes even a school

In this sentence, English naturally translates it as to school or to the school, depending on context.

Veniunt is from the verb venire, meaning to come.

Its grammar is:

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

So it means:

• they come
• or, depending on context, they are coming

In this sentence, with hodie, it is naturally understood as they come today / are coming today.

Yes. Neque ... neque is a very common alternative and means the same thing as nec ... nec.

So these are both fine in meaning:

• Nec Lucia nec Marcus hodie ad scholam veniunt
• Neque Lucia neque Marcus hodie ad scholam veniunt

A learner should simply recognize both patterns as meaning neither ... nor.