Serva pocula pura in mensa proponit, ut convivae bibere possint.

Because serva is in the nominative singular, which is the normal case for the subject of a finite verb in Latin.

Here, the verb proponit means she sets out / places, so we need a singular subject: serva = the slave-woman / maidservant.

A learner may notice that serva could also be ablative singular in some contexts, but here it is understood as nominative because:

• there is no preposition calling for the ablative
• the sentence needs a subject for proponit
• the meaning fits naturally

Because poculum is a neuter noun of the second declension.

For neuter nouns:

• nominative singular = poculum
• accusative singular = poculum
• nominative plural = pocula
• accusative plural = pocula

So pocula can be either nominative plural or accusative plural. In this sentence, it is accusative plural because it is the thing being set out by the servant.

This is a very common point for English speakers: in Latin, neuter plural nouns often end in -a.

Because pura agrees with pocula, and pocula is neuter plural.

Latin adjectives must agree with the nouns they describe in:

• gender
• number
• case

So:

• pocula = neuter plural accusative
• pura = neuter plural accusative

If the noun were feminine plural, then puras would make sense. But since pocula is neuter, the adjective must also take the neuter plural form: pura.

Literally, purus, pura, purum can mean pure, clean, or clear, depending on context.

With pocula meaning cups, the most natural sense is usually clean cups or spotless cups, not morally pure cups.

So the adjective keeps its basic meaning, but context tells you which English word sounds most natural.

Because in takes different cases depending on the meaning:

• in + ablative = in / on a place, showing location
• in + accusative = into / onto a place, showing motion toward

Here the cups are being placed on the table, so the phrase expresses location or position, not movement into the inside of something. Therefore Latin uses in mensa.

For a learner, this is a useful rule to remember:

• in mensa = on the table
• in mensam = onto the table

Proponit comes from propono, proponere, proposui, propositum.

Its basic idea is to put forward, set out, or place before. In this context, it means something like:

• sets out
• places on display
• puts out

So serva pocula pura in mensa proponit suggests that the servant is arranging the clean cups on the table for use.

It is a little more specific than a very plain ponit. The prefix pro- adds the sense of putting something forward or out where it can be used or seen.

Here ut introduces a purpose clause.

That means it tells you why the servant sets out the cups:

• Serva ... proponit = the servant sets out the cups
• ut convivae bibere possint = so that the guests may be able to drink

So ut here means so that or in order that.

This is one of the most important uses of ut in Latin.

Because after ut in a purpose clause, Latin normally uses the subjunctive.

So:

• possunt = indicative, they are able
• possint = subjunctive, they may be able / can, in a purpose setting

The clause is not just stating a fact; it expresses the intended result or purpose of the action. The servant sets out the cups so that the guests can drink. That is exactly the kind of idea Latin marks with ut + subjunctive.

Also, since the main verb proponit is present, Latin uses the present subjunctive in the purpose clause: possint.

Because possum normally takes a complementary infinitive.

So:

• possum bibere = I am able to drink
• possunt bibere = they are able to drink
• possint bibere = they may be able to drink

In this sentence, possint means may be able, and bibere gives the action they are able to do: to drink.

This construction is very common in Latin:

• potest venire = he can come
• possunt videre = they can see
• possint bibere = they can drink

Here convivae is nominative plural and is the subject of possint.

That can be confusing, because convivae could also be:

• genitive singular
• dative singular
• nominative plural
• vocative plural

But in this sentence, it must be nominative plural because it is the people who may be able to drink.

So the structure is:

• convivae = the guests
• bibere = to drink
• possint = may be able

Together: so that the guests may be able to drink

Because conviva is one of those Latin nouns that belong to the first declension but can refer to a male person.

English speakers often learn early that:

• first declension = usually feminine

That is often true, but not always. Some first-declension nouns are masculine, especially words referring to male people or borrowed patterns from Greek.

So conviva, convivae means guest, dining companion, and it can refer to:

• a man
• a woman
• a mixed group, depending on context

In this sentence, convivae simply means the guests.

Because bibere can be used absolutely, meaning simply to drink.

Latin does not always need to say exactly what is being drunk if it is obvious from context. Here, the clean cups make the situation clear: the guests are being given the means to drink.

So bibere does not need an object like vinum or aquam in order to make sense.

English does the same thing:

• The guests can drink.

You do not always have to add wine or water.

Latin word order is more flexible than English word order because the endings show the grammar.

This sentence is arranged quite naturally:

• Serva = subject first
• pocula pura = object with its adjective
• in mensa = place
• proponit = verb
• ut convivae bibere possint = purpose clause

A very literal structural reading is:

• The servant
• the clean cups
• on the table
• sets out
• so that the guests may be able to drink

Latin often puts the main verb near the end of its clause, and then adds a purpose clause after it. That is exactly what happens here.

Not in this structure.

If Latin wants to express a clear purpose clause with a finite verb, ut is the normal marker. Without ut, the sentence would no longer clearly say so that the guests may drink.

Latin does have other ways to express purpose, such as:

• a gerundive construction in some contexts
• a relative clause of purpose in some contexts

But for this sentence, ut + subjunctive is the straightforward and standard way to express the purpose.

That comma is a matter of modern punctuation, not ancient Latin grammar.

Editors and textbooks often put a comma before a subordinate clause introduced by ut because it helps readers see the sentence structure more clearly.

So the comma is useful for reading, but the real grammatical signal is not the comma. The real signal is:

• ut
• followed by the subjunctive verb possint

That is what tells you this is a purpose clause.