Iuveni mendacium non dicendum est, si amicitiam servare vult.

A lie must not be told by the young man, if he wants to preserve friendship.

Questions & Answers about Iuveni mendacium non dicendum est, si amicitiam servare vult.

What case is iuveni, and what is it doing in the sentence?

Iuveni is dative singular of iuvenis, meaning young man, young person, or youth.

Here it is not an indirect object in the usual sense. It is a dative of agent with the passive periphrastic construction. That means it marks the person on whom the obligation rests.

So:

• iuveni = for the young man / by the young man
• more naturally in English: the young man must...

In other words, Latin says something like A lie is not to be told by the young man, where English prefers The young man must not tell a lie.

Why does Latin use dicendum est here?

Dicendum est is a very common Latin way to express necessity or obligation.

It is made of:

• dicendum = the gerundive of dico (to say / tell)
• est = is

Together, dicendum est literally means must be said or is to be said.

With the negative:

• non dicendum est = must not be said

Because the sentence also has iuveni, the full sense becomes:

• iuveni mendacium non dicendum est
  = the young man must not tell a lie

This is called the passive periphrastic.

Does dicendum agree with mendacium?

Yes. The gerundive dicendum agrees with mendacium in:

• gender: neuter
• number: singular
• case: nominative

So:

• mendacium = neuter singular
• dicendum = neuter singular nominative

That agreement helps show that mendacium is the thing that is not to be said.

Is mendacium nominative or accusative here?

Here it is best understood as nominative singular.

Why? Because in the passive periphrastic, the thing that must be done is treated as the grammatical subject:

• mendacium non dicendum est
  literally: a lie is not to be said

Since mendacium is a neuter noun, its nominative and accusative singular forms look the same. But its role in the sentence is that of the subject, so grammatically it is nominative.

Why is the person expressed by the dative iuveni instead of ab iuvene?

Because with the passive periphrastic, Latin normally uses the dative of agent, not ab + ablative.

Compare:

• ordinary passive: mendacium ab iuvene dicitur
  = the lie is told by the young man
• passive periphrastic: mendacium iuveni dicendum est
  = the lie must be told by the young man / the young man must tell the lie

So the construction with -ndus + est regularly takes a dative for the person responsible.

What exactly does non negate in mendacium non dicendum est?

Non negates the whole idea of obligation:

• dicendum est = must be said
• non dicendum est = must not be said

So the sentence does not mean merely is not being said. It means it ought not to be said or it must not be said.

That is an important difference.

Why is servare an infinitive?

Because it depends on vult.

• vult = he wants
• servare = to preserve / to keep

Latin often uses volo with an infinitive, just like English uses want to:

• amicitiam servare vult
  = he wants to preserve friendship

So servare is the complementary infinitive after vult.

Why is it vult and not velit?

Because this is a straightforward if-clause expressing a real or open condition:

• si amicitiam servare vult
  = if he wants to preserve friendship

Latin commonly uses:

• si + indicative for a real/open condition

So vult is perfectly normal here.

If Latin used velit, that would usually suggest a different nuance, often more potential, generalized, or part of a different stylistic context. But in this sentence, vult is the expected form.

Why is amicitiam in the accusative?

Because amicitiam is the direct object of servare.

• servare = to preserve / keep
• what is being preserved? amicitiam = friendship

So:

• amicitiam servare = to preserve friendship

Why is the word order different from English?

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

This sentence is arranged as:

• Iuveni — the person responsible
• mendacium — the thing involved
• non dicendum est — the obligation
• si amicitiam servare vult — the condition

A very literal order would be:

• For the young man, a lie is not to be told, if he wants to preserve friendship

English usually reshapes that into something smoother, such as:

• A young man must not tell a lie if he wants to preserve friendship

So the Latin order is grammatical and natural, even though it does not match English habits.

Could Latin also say Iuvenis mendacium non debet dicere?

Yes, absolutely. That would also mean:

• The young man ought not to tell a lie
• The young man must not tell a lie

But the feel is a little different.

• Iuvenis mendacium non debet dicere uses debeo and is more directly like English must/ought to
• Iuveni mendacium non dicendum est uses the passive periphrastic, which is a very characteristic Latin way to express necessity

So both are correct, but the original sentence is especially useful because it teaches an important Latin construction.

Why is there no word for a or the in iuveni, mendacium, and amicitiam?

Because Latin has no articles like English a, an, or the.

So:

• iuveni can mean to a young man, to the young man, or simply for a young man, depending on context
• mendacium can mean a lie or the lie
• amicitiam can mean friendship, a friendship, or the friendship, depending on context

English has to choose an article when translating, but Latin does not.

What is the most literal way to understand the whole sentence grammatically?

A very literal unpacking would be:

• Iuveni = for/by the young man
• mendacium = a lie
• non dicendum est = is not to be said
• si amicitiam servare vult = if he wants to preserve friendship

So the sentence is literally:

• A lie is not to be said by the young man, if he wants to preserve friendship

That literal version sounds awkward in English, but it shows the Latin structure clearly. The natural English meaning is:

• A young man must not tell a lie if he wants to preserve friendship.