Magistra dicit verbum “amare” activum esse, “amari” autem passivum.

Magistra means female teacher or mistress/teacher. It is nominative singular, so it is the subject of the sentence.

Dicit means says. It is the 3rd person singular present active indicative of dicere.

So magistra dicit = the teacher says.

The feminine magistra is used because the teacher is female. If the teacher were male, Latin would normally use magister.

Here verbum most naturally means word.

So the sentence is talking about the forms amare and amari as grammatical items: the teacher is saying that the word/form amare is active, but amari is passive.

A useful point: Latin verbum can mean word in general, but it is also the source of the English word verb. In grammar contexts, that can sometimes confuse learners. In this sentence, it is best understood as word/form.

Yes, they are verb forms, but here they are being mentioned, not used.

English does this too:

• Run is a verb.
• To love is an infinitive.

In those examples, you are not telling someone to run or to love. You are talking about the words themselves.

That is what Latin is doing here with amare and amari.

They are both infinitives of amare:

• amare = present active infinitive = to love
• amari = present passive infinitive = to be loved

So the teacher is identifying their grammatical voice:

• amare is active
• amari is passive

This is a very common contrast in Latin grammar.

They are neuter because they agree with verbum, which is a neuter noun.

• verbum is neuter singular
• therefore activum and passivum are also neuter singular

So Latin is basically saying:

• the word amare to be active
• the word amari, however, passive

If the noun they described were masculine, you would expect activus/passivus. If feminine, activa/passiva.

Esse means to be, and it is part of an indirect statement after dicit.

Latin often uses this pattern after verbs like say, think, know, and hear:

• a subject in the accusative
• plus an infinitive

So magistra dicit verbum amare activum esse literally means:

The teacher says the word amare to be active.

Natural English usually changes that to:

The teacher says that the word amare is active.

So esse is there because Latin expresses the reported statement with an infinitive.

It is functioning as an accusative in the indirect statement, even though the form looks the same as the nominative.

That happens because verbum is a neuter second-declension noun, and in the singular:

• nominative: verbum
• accusative: verbum

So the forms are identical.

In this sentence, verbum is the logical subject of esse inside the indirect statement, and in Latin that subject goes into the accusative.

Because Latin often leaves out words that are easily understood from the previous part of the sentence.

After activum esse, the second half is understood as something like:

amari autem passivum esse

and even, if fully expanded:

verbum amari autem passivum esse

But Latin does not need to repeat everything. The omitted words are understood from context.

This kind of omission is very common and natural in Latin.

Autem usually means however, but, or on the other hand.

One important feature of autem is that it often comes second in its clause, not first. So Latin says:

• amari autem passivum

rather than putting autem at the very beginning.

That placement is normal Latin word order for autem.

So the contrast is:

• amare is active,
• amari, however, is passive.

Because classical Latin very often prefers the accusative-and-infinitive construction after verbs of saying, thinking, knowing, perceiving, and so on.

So instead of saying something exactly like English the teacher says that..., Latin commonly says:

• magistra dicit ... esse

This is one of the most important Latin sentence patterns to learn. English speakers often want a word like that, but Latin usually handles the idea differently.

You could, but it would sound awkward in English.

A very literal translation would be:

The teacher says the word amare to be active, amari however passive.

A better English translation is:

The teacher says that the word amare is active, but amari is passive.

Or even more naturally:

The teacher says that amare is active, but amari is passive.

So a literal translation can help you see the Latin structure, but a smoother English translation is usually better in the end.