Serva mensam ad cenam instruit.

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

• serva = the slave woman / maidservant as the doer of the action
• If it were the object, you would expect servam instead

So in this sentence, serva is the person doing the setting.

Serva is the feminine form of servus.

• servus = male slave
• serva = female slave, slave woman, maidservant

Depending on context, English might translate it as slave-girl, female slave, or maidservant.

Because mensam is accusative singular, which marks the direct object.

The direct object is the thing being acted on. Here, the servant is setting the table, so mensam is the thing being set.

From the dictionary form:

• mensa = table
• mensam = table as a direct object

So:

• mensa = the table as subject
• mensam = the table as object

Ad cenam means for dinner or more literally toward dinner / for the dinner meal.

• ad is a preposition that usually takes the accusative
• cenam is the accusative singular of cena, meaning dinner or the main meal

So ad cenam expresses purpose or occasion here: the table is being prepared for dinner.

Because the preposition ad takes the accusative case.

So:

• cena = dinner, in the nominative form
• cenam = dinner, after ad

This is a very common Latin pattern:

• ad + accusative

Instruit is:

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

It comes from the verb instruere.

So instruit means he/she/it prepares, arranges, equips, sets up.

In this sentence, since the subject is serva, it means she sets/prepares.

In general, instruere can mean things like:

• to arrange
• to equip
• to furnish
• to prepare
• to set in order

With mensam, it naturally means to set the table or lay the table.

So this is a good example of how Latin verbs often have a broad meaning, and the exact English translation depends on the object and context.

Because Classical Latin has no articles.

English says:

• the servant
• a servant
• the table
• a table

Latin just says:

• serva
• mensam

The reader figures out whether to translate with the, a, or sometimes no article at all from the context.

Yes. Latin word order is much more flexible than English word order because the endings show the grammatical roles.

So these could still mean roughly the same thing:

• Serva mensam ad cenam instruit.
• Mensam serva ad cenam instruit.
• Ad cenam serva mensam instruit.

The most important clues are the endings:

• serva = subject
• mensam = direct object
• cenam = object of ad
• instruit = verb

That said, word order can affect emphasis.

By itself, instruit only means he/she/it prepares. The verb ending does not tell you gender.

You know it means she here because the subject is serva, which is feminine.

So:

• instruit = he/she/it sets
• serva ... instruit = the female servant sets

Yes. Mensa is the normal Latin word for a table.

It can refer to an actual table, and in some contexts it can also be used in extended senses, but here it simply means the dining table being prepared.

So:

• mensa = table
• mensam instruit = sets the table

Yes. Both serva and mensa are first-declension nouns.

Their forms here are:

• serva = nominative singular
• mensam = accusative singular
• cena would also be first declension, and here it appears as cenam in the accusative singular

This sentence is a nice example of first-declension endings:

• -a for nominative singular
• -am for accusative singular

Yes. Depending on context, ad cenam can be understood as:

• for dinner
• for the dinner meal
• at dinner time
• more literally, toward dinner

In this sentence, the natural English is for dinner, because the table is being prepared with that purpose in mind.

A simple Classical-style pronunciation would be roughly:

SEHR-wah MEN-sahm ahd KEH-nahm in-STROO-it

A few helpful notes:

• v is pronounced like English w
• c is always hard, like k
• instruit is usually pronounced in three syllables: in-stru-it

You do not need perfect pronunciation to understand the grammar, but these points help.