Puella dicit monile aureum pretiosum esse, sed se id emere non posse.

Because Latin normally uses an indirect statement after verbs of saying, thinking, knowing, and perceiving.

In English, we say:

• The girl says that the golden necklace is expensive.

In Latin, instead of using a finite verb like est, Latin usually switches to:

• an accusative subject
• plus an infinitive verb

So monile aureum pretiosum esse means literally something like:

• the golden necklace to be expensive

That is the normal Latin way to express that the golden necklace is expensive.

In an indirect statement, the subject of the infinitive goes into the accusative.

So in monile aureum pretiosum esse, the necklace is the subject of esse, but because this is an indirect statement, it appears in the accusative.

A useful detail here is that monile is a neuter third-declension noun, and its nominative and accusative singular have the same form: monile.

So although it looks unchanged, its grammatical role is still that of the accusative subject of esse.

Because they agree with monile.

• monile = neuter singular
• aureum = neuter singular
• pretiosum = neuter singular

Aureum means golden and describes the necklace directly.

Pretiosum is a predicate adjective with esse, meaning expensive/precious.

Even in an indirect statement, adjectives still agree with the noun they describe. So both adjectives match monile in gender, number, and case.

Because Latin usually does not need a separate word for that in this kind of sentence.

English says:

• The girl says that...

Latin typically says:

• Puella dicit ...
• followed by an accusative-and-infinitive construction

So the idea of that is built into the structure itself. The indirect statement monile aureum pretiosum esse already means that the golden necklace is expensive.

Because se is the reflexive pronoun, and it refers back to the subject of the main clause, here puella.

So:

• se = herself
• referring back to the girl

Latin uses se when the person inside the subordinate idea is the same as the subject of the main verb.

If you used eam, it would usually mean her, referring to some other female person, not back to the girl who is speaking.

So:

• sed se id emere non posse = but that she cannot buy it
• with she = the same girl

Id is the direct object of emere.

• emere = to buy
• id = it/that

It refers back to monile, the necklace.

Because monile is neuter singular, the pronoun referring to it is also neuter singular: id.

So:

• se id emere non posse = that she cannot buy it

For the same reason we saw esse instead of est: this is still an indirect statement after dicit.

The second part is understood as another thing the girl says:

• sed se id emere non posse
• but that she cannot buy it

So Latin uses the infinitive posse rather than the finite verb potest.

If this were direct speech, it would be something like:

• Monile aureum pretiosum est, sed id emere non possum.

In indirect speech, non possum becomes se ... non posse.

Because posse regularly takes another infinitive.

• posse = to be able
• emere = to buy

So emere posse means to be able to buy.

In this sentence, it is negated:

• emere non posse = not to be able to buy

This is completely normal Latin structure, just like English to be able to buy.

It is another indirect statement.

Its parts are:

• se = accusative subject of the infinitive posse
• id = direct object of emere
• emere = infinitive depending on posse
• non posse = infinitive phrase meaning not to be able

So the structure is:

• [se] [id emere] [non posse]
• [she] [to buy it] [not to be able]

More naturally in English:

• that she cannot buy it

Because the negation is aimed at being able, not at buying by itself.

• id emere non posse = not to be able to buy it

This is the most natural way to express cannot buy it.

If you think about the meaning, the problem is not that she is refusing to buy it; the problem is that she is unable to buy it. So non goes with posse.

It would be something like:

Puella dicit: Monile aureum pretiosum est, sed id emere non possum.

Notice the changes:

• esse → est
• se disappears, because in direct speech the speaker says I
• non posse → non possum

So indirect speech turns the original first-person direct statement into a third-person report.

It may feel unusual from an English perspective, but it is normal Latin.

Latin word order is much more flexible than English word order. The endings show the grammatical relationships, so Latin does not rely as heavily on position.

This sentence is arranged quite neatly:

• Puella dicit
• then the first indirect statement: monile aureum pretiosum esse
• then sed
• then the second indirect statement: se id emere non posse

So the order is actually very logical, even if it is not the way English would phrase it.