Pater autem Carthaginem navigare mavult, nam Carthagini fullones periti esse dicuntur.

Because autem is usually postpositive in Latin: it tends to come after the first word, not before it.

So:

• Pater autem = Father, however... / But Father...

That word order is normal Latin.

Mavult means prefers or would rather.

It is the 3rd person singular present of the irregular verb malo, malle, malui.

So:

• navigare mavult = he prefers to sail

Latin often uses malo with an infinitive, just as English uses prefer with to + verb.

Because it depends on mavult.

After verbs like want, prefer, be able, and similar verbs, Latin often uses an infinitive:

• mavult navigare = he prefers to sail

So navigare is not the main verb of the sentence; it completes the meaning of mavult.

With names of cities and towns, Latin often shows motion toward a place by using the accusative without a preposition.

So:

• Carthaginem = to Carthage

That is why Carthaginem navigare means to sail to Carthage.

A learner should notice the contrast here:

• Carthaginem = to Carthage
• Carthagini = in Carthage

Here Carthagini means in Carthage.

This is commonly explained as a locative form, used especially with names of cities and towns to express place where. In this word, it looks the same as the dative.

So the sentence contrasts two different ideas:

• Carthaginem = movement to Carthage
• Carthagini = location in Carthage

This is a very common Latin construction with a passive verb of saying plus an infinitive.

Literally, it is:

• fullones = fullers
• periti esse = to be skilled
• dicuntur = are said

So:

• fullones periti esse dicuntur = fullers are said to be skilled

Latin often keeps the infinitive esse in this kind of reported statement.

Because in this sentence fullones is the subject of dicuntur, so periti agrees with it in the nominative plural.

• fullones = nominative plural subject
• periti = nominative plural adjective agreeing with fullones

If the sentence were active, the construction would be different:

• fullones peritos esse dicunt = they say that fullers are skilled

Notice something slightly tricky: fullones has the same form in nominative plural and accusative plural, so the visible clue is really periti/peritos.

Latin often includes esse in indirect statement after verbs of saying, thinking, knowing, and similar verbs.

So:

• periti esse dicuntur = are said to be skilled

Sometimes Latin can omit forms of esse in other contexts, but here keeping esse is completely normal and clear.

Periti means skilled, expert, or experienced.

Sometimes peritus can be followed by a word showing what someone is skilled in, but it does not have to be. Here the sense is simply that the fullers are skilled at their trade, and Latin leaves that understood from the context.

Latin word order is much more flexible than English word order because the endings show how the words function.

In this sentence, the order helps highlight ideas:

• Pater autem puts Father first, then adds however
• Carthaginem comes before navigare to make the destination clear early
• Carthagini is placed near the start of the second clause to stress in Carthage
• dicuntur comes at the end, which is very common in Latin

So the sentence may feel unusual in English order, but it is natural Latin.