Magistra dicit impium esse parentes contemnere, sicut nefas sit falsum iurare.

This is an indirect statement after dicit.

After verbs like dicit (says), Latin often does not use a that-clause the way English does. Instead, it uses an infinitive construction. So:

• Magistra dicit ... = The teacher says ...
• impium esse parentes contemnere = that despising one’s parents is impious

So the Latin structure is literally something like:

• The teacher says [to despise parents to be impious]

but in good English we translate it with that.

There is no separate accusative subject here because the subject of esse is the whole infinitive phrase parentes contemnere.

In many indirect statements, you get:

• dicit eum venire = he says that he is coming

where eum is the accusative subject of venire.

But here the idea being judged is not someone doing something; it is the action itself:

• parentes contemnere = to despise parents

That whole infinitive phrase functions as the subject of esse. So Latin does not need a separate accusative subject.

Because an infinitive phrase used as a subject is treated as neuter singular.

So:

• parentes contemnere = to despise parents
• this whole action is grammatically treated like a neuter singular idea
• therefore the predicate adjective is impium

This is very common in Latin:

• turpe est mentiri = it is shameful to lie
• difficile est hoc facere = it is difficult to do this

So impium esse parentes contemnere means to despise parents is impious.

Because contemnere takes a direct object in the accusative.

• contemnere aliquem = to despise someone
• parentes = parents in the accusative plural

So:

• parentes contemnere = to despise parents

A native English speaker might wonder whether some other case should be used, but with contemnere, the normal construction is simply accusative.

They are infinitives because Latin is talking about the actions themselves in a general way:

• parentes contemnere = despising parents / to despise parents
• falsum iurare = swearing falsely / to swear falsely

In the first half, the infinitive is also part of the indirect statement after dicit.

More broadly, Latin often uses infinitives after expressions like:

• impium est
• turpe est
• nefas est
• fas est

to express doing X is wrong/right/shameful/etc.

Here sicut means just as or just as in the same way.

It introduces a comparison:

• impium esse parentes contemnere
• sicut nefas sit falsum iurare

So the teacher is saying that despising one’s parents is impious, just as swearing falsely is wrong.

It is a comparison of moral judgments.

Because this clause is inside indirect speech, and subordinate clauses inside indirect speech often use the subjunctive in Latin.

If this were direct speech, it would likely be:

• Impium est parentes contemnere, sicut nefas est falsum iurare.

After magistra dicit, the main statement becomes infinitive-based, and the subordinate comparative clause introduced by sicut takes the subjunctive:

• sicut nefas sit falsum iurare

So sit is a good example of the subjunctive appearing in a subordinate clause within reported speech.

Nefas is a very common Latin word meaning something like:

• wrong
• forbidden
• against divine law
• an impious or taboo act

It is often used in the expression:

• nefas est = it is wrong / it is forbidden / it is an outrage

It is the opposite of fas, which refers to what is permitted by divine or sacred law.

So:

• nefas sit falsum iurare = that swearing falsely be wrong
  or more naturally,
• that it is wrong to swear falsely

Here falsum is a substantivized adjective, meaning something false or a false thing.

So literally:

• falsum iurare = to swear something false

Idiomatic English usually makes this:

• to swear falsely
• to swear a false oath

So falsum is the object of iurare. Latin often uses a neuter adjective this way, where English would prefer an adverb or a fuller noun phrase.

They are similar, but not identical.

• impium describes something as impious, lacking proper duty or reverence
• nefas describes something as forbidden or an outrage, especially in a sacred or moral sense

So impium often highlights a failure of pietas—the dutiful respect owed to gods, parents, and country. That makes it especially appropriate with parentes contemnere.

Nefas can sound even more absolute: something morally or religiously out of bounds.

So the sentence is not repeating the exact same word twice; it is using two closely related moral terms with slightly different shades of meaning.

Because Latin word order is much freer than English word order.

English depends heavily on position:

• The teacher says that despising parents is impious

Latin can move elements around for emphasis or style. In this sentence:

• impium esse comes before parentes contemnere
• falsum comes before iurare

This order helps foreground the moral judgment:

• impium
• nefas

before the actions being judged.

A more English-like order is possible in explanation, but the Latin order is natural and stylistically effective.

Yes. Both are good ways to understand it.

Latin infinitive subjects often translate naturally in either of these ways:

• parentes contemnere impium est = to despise parents is impious
• it is impious to despise parents

English usually chooses whichever sounds smoother in context. The Latin grammar is the same either way.

Latin often places the key idea first for emphasis. Here the moral verdict comes first:

• impium esse = to be impious

and only then the action is named:

• parentes contemnere

This can give the sentence a slightly weightier or more rhetorical feel. Latin authors do this all the time: they do not always present material in the order an English speaker expects.

So the order is not random; it helps stress the judgment before the deed.