Lucia et Marcus versus recitant; alii tacent.

They are both in the nominative singular, because they are the subject of recitant.

• Lucia is a first-declension name.
• Marcus is a second-declension name.
• et simply joins them: Lucia et Marcus = Lucia and Marcus.

Even though there are two people together, each name stays singular; the whole phrase is a compound subject.

Because the subject is Lucia et Marcus, which means two people. In English we would say Lucia and Marcus recite, not recites.

So recitant is third-person plural: they recite.

Recitant is the present active indicative, third-person plural of recitare.

So it means:

• they recite
• they are reciting in a simple present sense, depending on context

The ending -nt is a very common sign of a third-person plural verb in Latin.

Here versus is a noun, meaning verses or lines of poetry.

In this sentence it is the direct object of recitant, so it is in the accusative plural: Lucia and Marcus are reciting verses.

A useful detail: versus is a fourth-declension noun, and its accusative plural is also versus, so the form may look surprising if you are expecting an -os or -as ending.

No, not in meaning.

In this sentence, versus means verses, as in lines of poetry.

An English speaker may recognize the spelling because English versus ultimately comes from Latin, but here it is not the against word used in sports or legal names. It is simply the noun verse in the plural accusative.

Because Latin often uses adjectives substantively, meaning that the noun is understood instead of stated.

So alii literally means others, but in context it means the other people or the others.

It is:

• nominative plural
• masculine

The masculine plural can refer to:

• a group of men, or
• a mixed group of people

So alii tacent means the others are silent or the others keep quiet.

Because it is really alii = ali- + -i, and in careful spelling with macrons it is written alii with a long second i: alii or more fully aliī.

So the two i letters belong to two different parts of the word, not one extra-long sound written oddly by accident.

This double-i spelling is normal in forms like this.

Tacent is the present active indicative, third-person plural of tacere, meaning to be silent or to keep quiet.

It is tacent and not tacet because its subject, alii, is plural:

• alii tacent = the others are silent
• alius tacet would be the other person is silent

Again, the ending -nt shows third-person plural.

Because Latin usually does not need to state subject pronouns unless they are emphasized.

The verb ending already tells you the subject is they:

• recitant = they recite
• tacent = they are silent / they keep quiet

Latin can add ei, illi, or another pronoun if it wants emphasis, contrast, or clarity, but normally the verb ending is enough.

Latin has no articles, so there is no separate word for the or a/an.

That means:

• versus can mean verses, the verses, or sometimes some verses, depending on context
• alii can mean other people or the others

Also, Latin does not need a separate word for are in alii tacent, because tacent already means they are silent / they keep quiet.

No. Latin word order is much freer than English word order because the endings show how the words function.

This sentence has a fairly straightforward order:

• Lucia et Marcus = subject
• versus = object
• recitant = verb
• alii = subject
• tacent = verb

But Latin could rearrange parts for emphasis, especially the object and verb. For example, Lucia et Marcus recitant versus would still be understandable.

The semicolon separates two closely related independent clauses:

• Lucia et Marcus versus recitant
• alii tacent

So it works a bit like meanwhile or while the others are silent, without actually adding another connecting word.

Also, punctuation in printed Latin is mostly an editorial choice. Ancient texts were not originally punctuated in exactly the same modern way.