Serva catinum cum pomis et pane ad mensam fert.

Because serva is in the nominative singular, which is the case normally used for the subject of a sentence in Latin.

• serva = female slave, maid, or servant-girl
• It is a first-declension noun
• Its nominative singular ending is -a

So serva is the person doing the action of fert.

Catinum is the direct object. It is the thing being carried.

It is in the accusative singular, which is the case Latin usually uses for a direct object.

• catinum = bowl or dish
• It is a neuter noun
• In many neuter nouns of the second declension, the nominative and accusative singular are the same, so catinum can be either depending on context
• Here it must be the object because serva is already the subject

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

A very common neutral Latin pattern is:

• subject
• object
• other phrases
• verb

So Serva catinum cum pomis et pane ad mensam fert is perfectly normal Latin.
Even if the words were rearranged, the endings would still show their roles.

Pomis is ablative plural.

It is ablative because it follows cum, and cum meaning with takes the ablative case.

• pomum = apple or fruit
• pomis = with apples

So cum pomis means with apples.

Because cum takes the ablative, not the accusative.

• panis = bread
• pane = with bread or by/with bread, depending on context
• panem would be bread as a direct object

So in this sentence:

• cum pomis et pane = with apples and bread

Here cum means with in the sense of accompaniment.

Latin commonly uses:

• cum
  • ablative

So:

• cum pomis = with apples
• cum pane = with bread

This is one of the most basic and common preposition-case pairings in Latin.

Ad mensam means to the table.

The preposition ad usually expresses motion toward something, and it takes the accusative case.

• mensa = table
• mensam = to the table / toward the table

So the sentence shows movement: the servant is carrying the bowl to the table.

Because Classical Latin has no articles.

So a noun like serva can mean:

• a female slave
• the female slave

And catinum can mean:

• a bowl
• the bowl

You decide from the context which English article is best.

In sense, it most naturally describes the bowl: it is a bowl with apples and bread in it or accompanying it.

So the idea is:

• the servant carries a bowl containing / accompanied by apples and bread to the table

Grammatically, Latin often leaves this kind of relationship slightly looser than English does, but that is the most natural understanding here.

Because the sentence is talking about:

• apples = more than one, so plural
• bread = treated as a mass noun, so singular

This is very natural in both Latin and English. English also often says apples and bread, not necessarily apples and breads.

We know from the case endings, not mainly from the position of the words.

In this sentence:

• serva = nominative singular → subject
• catinum = accusative singular → direct object
• pomis and pane = ablative after cum
• mensam = accusative after ad
• fert = verb, he/she/it carries

So even if the sentence were rearranged, the endings would still tell you the basic grammar.

Fert is third person singular in the present tense.

It means:

• he carries
• she carries
• it carries

Since the subject is serva, here it means she carries.

It comes from the irregular verb ferre, meaning to carry or to bear.

No. Ferre is an irregular verb.

Some common forms are:

• fero = I carry
• fers = you carry
• fert = he/she/it carries
• ferimus = we carry
• fertis = you all carry
• ferunt = they carry

So fert may look a little unusual, but it is a very common form.

Yes. Serva is specifically feminine, meaning a female slave or maidservant.

The masculine equivalent is:

• servus = male slave / servant

So:

• Serva fert = the female slave carries
• Servus fert = the male slave carries

A simple way to divide it is:

• Serva = subject
• catinum = direct object
• cum pomis et pane = prepositional phrase with cum
• ad mensam = prepositional phrase with ad
• fert = verb

So the overall pattern is:

subject + object + prepositional phrases + verb