Magistra dicit bonum participem disputationis non solum audire, sed etiam aperte respondere.

Particeps is the dictionary form, or nominative singular. In this sentence, the word is not the subject of the infinitives; it is the person being described in the statement after dicit. Because of that, Latin puts it in the accusative: participem.

This happens because Latin often uses an accusative + infinitive construction after verbs like dicit (says).

So:

• particeps = nominative, a participant
• participem = accusative, a participant as the object/form used in indirect statement

For the same reason: both words are in the accusative singular.

• bonus particeps would be nominative singular: a good participant as a subject
• bonum participem is accusative singular: a good participant inside the indirect statement

The adjective must agree with the noun it describes in case, number, and gender.

So:

• bonum agrees with participem
• both are accusative singular masculine/feminine here

Because after dicit, Latin is using indirect statement.

English often says:

• The teacher says that a good participant ... listens and responds.

Latin typically does this differently:

• Magistra dicit
  • accusative subject
    • infinitive verb(s)

So:

• bonum participem = the subject of the reported statement, in the accusative
• audire and respondere = infinitives expressing what that participant does

This is a very common Latin pattern, often called the accusative and infinitive construction.

There is no separate word for that here, because Latin usually does not need one in this kind of sentence.

English says:

• The teacher says that ...

Latin often says:

• The teacher says ...
  • accusative + infinitive

So the idea of that is built into the structure itself.

In other words:

• Magistra dicit = The teacher says
• bonum participem ... audire ... respondere = that a good participant listens ... and responds ...

Disputationis is a genitive singular form, meaning of the discussion or of the debate.

It depends on participem:

• particeps disputationis = participant in / of the discussion

Latin often uses the genitive where English might prefer:

• participant in the discussion
• participant of the discussion (less natural in English, but closer to the Latin structure)

So disputationis tells us what the person is participating in.

This is a very common pairing meaning:

• not only ... but also ...

Here it links two infinitives:

• non solum audire
• sed etiam aperte respondere

So the structure is:

• not only to listen
• but also to respond openly

It is important that the two parts are parallel. Both audire and respondere depend on the same idea and match each other grammatically.

Aperte is an adverb. It means something like:

• openly
• clearly
• frankly

It modifies respondere:

• aperte respondere = to respond openly / clearly

A learner might notice that aperte looks related to apertus (open). That is correct: it is the adverb form.

No. Even though the words look similar in English, particeps here means participant or one who takes part.

So:

• particeps = participant
• participle in grammar = a completely different idea

This is an easy thing for English speakers to misread at first.

Latin word order is much more flexible than English word order because Latin shows grammatical relationships through endings, not mainly through position.

So although the sentence begins:

• Magistra dicit ...

the rest can be arranged in different ways without changing the core meaning.

This order puts:

• bonum participem disputationis together as a unit
• then the paired infinitives:
  • non solum audire
  • sed etiam aperte respondere

The order is quite natural and makes the contrast clear.

Yes. Magistra is in the nominative singular, so it is the subject of dicit.

So:

• Magistra = the teacher
• dicit = says

Together:

• Magistra dicit = The teacher says

By contrast, bonum participem is accusative, so it is not the main subject of dicit; it is the subject of the infinitives inside the indirect statement.

Yes, depending on context, English might naturally use should:

• The teacher says that a good participant should not only listen, but also respond openly.

Strictly speaking, the Latin sentence itself does not contain a separate word meaning should. The infinitives simply express what the teacher says a good participant does. But in English, when someone is stating a general principle, adding should can sound more natural.

So both of these may work in translation, depending on tone:

• The teacher says that a good participant not only listens, but also responds openly.
• The teacher says that a good participant should not only listen, but also respond openly.