Căpitanul este pe navă.

In Romanian, the definite article is usually attached to the end of the noun, not written as a separate word like English the.

• căpitan = captain
• căpitanul = the captain

Here, -ul is the masculine singular definite article.

Este means is. It is the 3rd person singular form of a fi = to be.

So:

• Căpitanul este pe navă = The captain is on the ship

In everyday speech, Romanians often use the shorter form e:

• Căpitanul e pe navă

Both are correct.

Normally, no. In a sentence like this, Romanian usually keeps the verb to be in the present tense.

So:

• Căpitanul este pe navă = correct
• Căpitanul pe navă = not standard Romanian

Here, pe is a preposition meaning on.

So pe navă means on the ship or aboard.

This is different from another common use of pe in Romanian, where it can mark certain direct objects. In this sentence, it is simply a location word.

This is a very natural Romanian way to express location. After a preposition, Romanian often uses a noun without the definite article when the idea is more like aboard, at sea, in school, in town, and so on.

So pe navă can feel like on board or aboard ship.

Compare:

• pe navă = on board / on the ship in a general locational sense
• pe o navă = on a ship
• pe nava aceea = on that ship

So the version in your sentence is normal and idiomatic.

No. Romanian usually does not need a subject pronoun unless you want emphasis or contrast.

• Căpitanul este pe navă = The captain is on the ship
• El este pe navă = He is on the ship

If the subject is already named as căpitanul, adding el would usually be unnecessary.

Yes, Romanian word order is fairly flexible, but the most neutral order here is:

• Căpitanul este pe navă

You can change the order for emphasis:

• Pe navă este căpitanul

That sounds more marked, as if you are emphasizing where the captain is, or contrasting it with another place.

The letter ă is pronounced like the a in English about: a short, relaxed uh sound.

So:

• Căpitanul ≈ kuh-pee-TA-nul
• navă ≈ NA-vuh

A rough pronunciation of the whole sentence is:

• kuh-pee-TA-nul YEH-ste peh NA-vuh

The stress is usually:

• căpitaNUL
• ESte
• NAvă

Yes. They matter in standard writing and pronunciation.

• ă is not the same as a
• Căpitanul and navă should be written with ă

You may sometimes see Romanian typed without diacritics online, but as a learner, it is best to learn and use the correct spelling.

• căpitanul is masculine singular
• navă is feminine singular

This matters because Romanian articles and adjectives change depending on gender and number.

For example:

• căpitanul obosit = the tired captain
• nava mare = the big ship

So even in a short sentence like this, gender is already working in the background.