Pudor puerum monet ne mendacium dicat.

The subject is pudor.

You can tell because:

• pudor is in the nominative case, the usual case for the subject
• monet is 3rd person singular, and it agrees with pudor
• puerum is accusative, so it cannot be the subject of monet

So the basic main clause is Pudor puerum monet = Shame / a sense of shame warns the boy.

Puerum is the direct object of monet.

The verb moneo, monere often means warn, advise, or remind, and the person being warned is put in the accusative:

• puerum monet = warns the boy

So:

• pudor = the one doing the warning
• puerum = the person being warned

Pudor is a noun meaning something like:

• shame
• modesty
• sense of shame
• sense of honor

In this sentence, a sense of shame is often the most natural way to understand it.

Latin is very comfortable making an abstract noun the subject of a verb. English can do this too, but it often sounds more natural if we expand it a little, such as his sense of shame warns the boy or the boy’s sense of shame warns him.

This is a common pattern with verbs like moneo:

• verb of warning/advising
• followed by ne or ut
• with a subjunctive verb

So monet ne mendacium dicat means warns him not to tell a lie.

You can think of ne mendacium dicat as the content of the warning.

Because this is not just an ordinary negation of a statement. It is part of a dependent clause expressing what someone is warned not to do.

After verbs like moneo, Latin normally uses:

• ut
  • subjunctive for a positive idea
• ne
  • subjunctive for a negative idea

So:

• monet ut veniat = warns/advises him to come
• monet ne veniat = warns/advises him not to come

Non would not be the normal way to make this construction negative.

Because it is in a subordinate clause after monet.

After verbs of warning, urging, commanding, persuading, and similar ideas, Latin regularly uses the subjunctive in the following clause. So:

• dicit would mean he says
• dicat here means that he say / should say, or in smoother English, simply to say

Since the clause is negative:

• ne mendacium dicat = not to tell a lie

So the subjunctive is required by the construction.

This is because of sequence of tenses.

The main verb is monet, which is present tense. That is a primary tense, so Latin normally uses the present subjunctive for an action that is simultaneous with or later than the main verb.

So:

• monet ... dicat = warns ... not to say
• if the main verb were past, you would often expect diceret

For example:

• monuit ne mendacium diceret = he warned him not to tell a lie

Yes.

Even though puerum is accusative in the main clause, it is understood that the boy is the one who would tell the lie in the subordinate clause.

So the sense is:

• Shame warns the boy [that he should not] tell a lie

Latin often leaves that subject unexpressed when it is obvious from context. If English spelled everything out, it would be warns the boy that he should not tell a lie.

No.

This is an important point:

• puerum is the object of monet
• mendacium is the object of dicat

So the sentence divides like this:

• Pudor puerum monet
• ne mendacium dicat

Inside the second part, mendacium belongs only to dicat, not to monet.

Because it is the direct object of dicat.

Latin often says mendacium dicere, literally to say a lie, where English usually says to tell a lie.

So:

• mendacium = accusative singular
• object of dicat

This is perfectly normal Latin usage.

It is one common way.

Latin can express this idea in more than one way:

• mendacium dicere = to tell a lie
• mentiri = to lie

So this sentence could have used a different verb, but mendacium dicat is completely standard and clear.

They are:

• monet from moneo, monere
• dicat from dico, dicere

More fully:

• monet = 3rd person singular, present, active, indicative
• dicat = 3rd person singular, present, active, subjunctive

Those forms tell you that:

• monet states the main action
• dicat is the dependent subjunctive action inside the ne clause

The word order can be changed. Latin word order is much more flexible than English word order because the cases show each word’s role.

This sentence could be rearranged in various ways without changing the basic meaning, for example:

• Puerum pudor monet ne mendacium dicat
• Pudor ne mendacium dicat puerum monet

However, the given order is natural and clear. It presents:

1. the subject, pudor
2. the person affected, puerum
3. the main verb, monet
4. the content of the warning, ne mendacium dicat

So the original order is a good straightforward Latin sentence.