Dum pueri currunt, soror eorum iocum novum narrat et omnes iterum rident.

Here dum means while.

So Dum pueri currunt means While the boys are running.

In Latin, dum is a very common way to introduce a clause describing something happening at the same time as the main action.

Currunt is present tense because the sentence describes an action happening at the same time as the main action:

• Dum pueri currunt = While the boys are running
• soror eorum ... narrat = their sister tells ...
• omnes ... rident = everyone laughs

Latin often uses the present indicative after dum when it means while.

Because pueri is the subject of currunt.

• pueri = the boys (nominative plural)
• currunt = run / are running

If it were pueros, that would be accusative plural, which usually marks a direct object, not the subject.

So:

• pueri currunt = the boys run
• not the boys as an object

The ending tells you:

• pueri = plural subject
• currunt = they run (3rd person plural)

The verb ending -unt shows a third-person plural subject, so it matches pueri.

Both are possible in Latin.

• soror eorum
• eorum soror

Both mean their sister.

Latin word order is more flexible than English because the endings show the grammatical roles. The version here probably puts soror first because the writer wants to introduce the sister before adding eorum.

So this is mostly a matter of style or emphasis, not a change in basic meaning.

This is a very common question.

Suus, -a, -um usually refers back to the subject of its own clause.

In the main clause, the subject is:

• soror

So if Latin used suus here, it would naturally refer back to the sister, not to the boys.

But the meaning is the sister of the boys, so Latin uses:

• eorum = of them / their

That points back to pueri, not to the subject soror of the main clause.

Eorum is genitive plural.

It is used to show possession:

• soror eorum = their sister
• literally, the sister of them

So the genitive answers the question whose sister? Answer: eorum.

Because iocum is the direct object of narrat.

• narrat = tells
• What does she tell?
• iocum novum = a new joke

So iocum is accusative singular because it is the thing being told.

Because novum is an adjective modifying iocum, and adjectives in Latin agree with the nouns they describe in:

• gender
• number
• case

Here:

• iocum = masculine, singular, accusative
• novum = masculine, singular, accusative

So novum matches iocum exactly.

Narrat means tells or relates.

In this sentence:

• iocum novum narrat = she tells a new joke

Latin narrare is often used for telling a story, an account, or something spoken aloud to others. Here it works naturally with iocum.

Here omnes is being used as a pronoun meaning everyone or all of them.

It refers to the people already involved in the scene. In context, that probably means the whole group.

So:

• omnes iterum rident = everyone laughs again / they all laugh again

Latin often uses omnes by itself this way.

Here omnes is nominative plural, because it is the subject of rident.

• omnes = all (the people)
• rident = laugh

So omnes is doing the action.

A learner may notice that omnes can also be accusative plural in form, but here the verb makes it clear that it is nominative: it is the subject of rident.

Latin normally uses the masculine plural for a mixed group of males and females.

So if omnes refers to:

• the boys
• and their sister
• and possibly others

then masculine plural is the normal choice.

This is similar to how many languages use a masculine plural as the default for mixed groups.

Iterum means again.

It modifies rident:

• omnes iterum rident = everyone laughs again

Latin adverbs are often quite flexible in position, so iterum could appear in different places without greatly changing the basic meaning.

Because et links two parts of the main statement:

• soror eorum iocum novum narrat
• et omnes iterum rident

So the structure is:

• While the boys are running,
• their sister tells a new joke
• and everyone laughs again

The dum clause gives background, and et connects the two main actions that follow.

Yes. Latin word order is much freer than English word order because Latin relies heavily on endings.

In this sentence, the order is fairly natural prose Latin:

• Dum pueri currunt
• soror eorum iocum novum narrat
• et omnes iterum rident

But Latin could rearrange parts for emphasis. For example, eorum soror instead of soror eorum would still be understandable.

English depends much more on word order to show who is doing what; Latin depends more on case endings and verb endings.

It has three parts:

1. Dum pueri currunt

   • subordinate clause introduced by dum
   • pueri = subject
   • currunt = verb

2. soror eorum iocum novum narrat

   • main clause
   • soror = subject
   • eorum = genitive dependent on soror
   • iocum novum = direct object
   • narrat = verb

3. et omnes iterum rident

   • another coordinated clause
   • omnes = subject
   • iterum = adverb
   • rident = verb

So the sentence is a while-clause plus two linked main actions.