O primo viaja com Ana.

Because primo is a masculine singular noun meaning male cousin.

• o = the for masculine singular nouns
• a = the for feminine singular nouns

So:

• o primo = the male cousin
• a prima = the female cousin

Portuguese often omits subject pronouns when the verb already makes the subject clear.

In O primo viaja com Ana, the subject is already stated as O primo, so adding ele would be unnecessary.

Portuguese does this much more often than English. In English, you usually must say the subject; in Portuguese, it is often clear from context or from the verb form.

Viaja is the 3rd person singular present indicative form of viajar (to travel).

Conjugation of viajar in the present:

• eu viajo
• você/ele/ela viaja
• nós viajamos
• vocês/eles/elas viajam

So viaja matches:

• ele viaja
• ela viaja
• você viaja
• or a singular noun like o primo viaja

It can often mean either, depending on context.

In Portuguese, the simple present can express:

• a habitual action: The cousin travels with Ana
• a present/current action in some contexts: The cousin is traveling with Ana

If you want to make the ongoing action especially clear in Brazilian Portuguese, you often use:

• O primo está viajando com Ana. = The cousin is traveling with Ana.

So viaja is simple present, but context helps determine the best English translation.

Because Ana is a proper name, and in standard Portuguese you usually do not put an article before it in this kind of sentence.

So:

• com Ana = with Ana

In some regions of Brazil, people do use an article before first names in everyday speech:

• com a Ana

That is common in some varieties, but com Ana is fully correct and very standard.

Here, com means with.

Examples:

• com Ana = with Ana
• com o primo = with the cousin
• com amigos = with friends

It is a very common preposition. Depending on context, it can also appear in expressions where English uses different wording, but in this sentence the meaning is simply with.

Because this follows the very common Portuguese pattern:

• Subject + Verb + Complement

So here:

• O primo = subject
• viaja = verb
• com Ana = prepositional phrase/complement

This is also the most natural neutral word order in English:

• The cousin travels with Ana

Other word orders are possible in Portuguese for emphasis or style, but this sentence uses the basic standard order.

Yes, but the meaning changes.

• O primo viaja com Ana. = The cousin travels with Ana.
• Um primo viaja com Ana. = A cousin travels with Ana.

So:

• o = the definite article
• um = a/an indefinite article

Using o suggests the cousin is a specific person already known in the conversation.

In Brazilian Portuguese, viaja is pronounced approximately like:

• vee-AH-zha

A rough breakdown:

• vi sounds like vee
• a is a separate vowel sound
• ja in Brazilian Portuguese sounds like zha/zhah, with the j like the s in measure

So the stress is on the middle syllable: vi-A-ja.

A rough pronunciation guide for Brazilian Portuguese is:

O primo viaja com Ana.
oo PREE-moo vee-AH-zha kong AH-na

A few notes:

• o often sounds like oo in unstressed position
• primo = PREE-moo
• viaja = vee-AH-zha
• com is often pronounced close to kong or a nasalized kohng
• Ana = AH-na

This is only an approximation in English spelling, but it helps with the general sound.

Because Portuguese nouns referring to people often show grammatical gender that matches biological sex in this kind of word:

• primo = male cousin
• prima = female cousin

So if the cousin were female, the sentence would be:

• A prima viaja com Ana.

This is an important difference from English, where cousin does not show gender.

The most natural reading is that the cousin travels together with Ana, so yes, Ana is understood to be accompanying him.

The phrase com Ana means with Ana, which normally implies Ana is with him during the action.

So the sentence suggests a shared action: they travel together.