Dum tempestas in mari manet, nautae in portu tacent.

Here dum means while or as long as. It introduces a subordinate clause:

dum tempestas in mari manet = while / as long as the storm remains at sea

Both meanings are possible in Latin, and the exact nuance depends on context.

Both verbs are present indicative:

• manet = remains / stays
• tacent = are silent / keep quiet

Latin often uses the present tense straightforwardly when describing something happening now or generally. In this sentence, both actions are presented as happening at the same time: the storm remains at sea, and the sailors stay quiet in the harbor.

Tempestas is nominative singular and is the subject of manet.

So:

• tempestas = storm
• manet = remains

Together, they mean the storm remains.

A learner might expect the subject to look more obvious, but in Latin the verb ending and case ending help show the grammar.

Here nautae is nominative plural, the subject of tacent.

So:

• nautae = sailors
• tacent = are silent

We know it is plural because tacent is a third person plural verb. If the sentence had only one sailor, you would expect nauta tacet.

Because in takes the ablative when it means in or on in the sense of location.

So:

• in mari = in the sea / at sea
• in portu = in the harbor

If there were motion into a place, Latin would usually use in with the accusative instead:

• in portum = into the harbor

That is an important Latin distinction:

• in + ablative = location
• in + accusative = motion toward

Because mare is a third-declension neuter i-stem noun, and its ablative singular is mari.

Its main forms are:

• mare = nominative singular
• maris = genitive singular
• mari = ablative singular

Since in here requires the ablative for location, Latin uses mari.

Tacent comes from tacere, which means to be silent, to keep quiet, or to say nothing.

So nautae in portu tacent means the sailors are quiet or silent in the harbor. It is not just about making no sound physically; it can also suggest a deliberate silence.

Latin word order is much more flexible than English word order because Latin uses endings to show grammatical function.

English depends heavily on position:

• The sailors are silent

Latin can move words around more freely because:

• nautae shows the subject
• tacent shows a plural verb
• in portu clearly gives location

In this sentence, the subordinate clause comes first:

Dum tempestas in mari manet, nautae in portu tacent.

That order is very natural in Latin. It sets the scene first, then gives the main statement.

Latin has no definite article and no indefinite article. In other words, it has no direct equivalent of the, a, or an.

So:

• tempestas can mean storm or the storm
• nautae can mean sailors or the sailors
• portu can mean harbor or the harbor

Which English article is best depends on context and translation style.

The clause introduced by dum is the subordinate clause:

dum tempestas in mari manet

The other clause is the main clause:

nautae in portu tacent

A good way to spot this is that dum acts like a marker: it tells you that what follows is dependent on the main statement.

Yes. Nauta is a good example of a first-declension noun referring to a male person.

That can feel strange to English speakers because learners often associate:

• first declension with feminine nouns

But some first-declension nouns are masculine, especially ones referring to occupations or roles, such as:

• nauta = sailor
• agricola = farmer
• poeta = poet

So nautae here is perfectly normal Latin.

Both are possible, but they emphasize slightly different ideas:

• while focuses on simultaneous time
• as long as focuses on duration / continued condition

So the sentence could suggest either:

• the sailors are silent during the time that the storm remains at sea
• the sailors are silent for as long as the storm remains at sea

Without more context, either understanding is reasonable.