Ela trabalha no tribunal.

Trabalhar is the infinitive, meaning to work.

In this sentence, the verb is conjugated for ela (she), so it becomes trabalha:

• eu trabalho = I work
• você/ele/ela trabalha = you/he/she works
• nós trabalhamos = we work

So Ela trabalha means She works.

Ela means she.

In Portuguese, subject pronouns are often optional when the context already makes the subject clear. So in many situations, you could simply say:

• Trabalha no tribunal.

However, because trabalha could also refer to he, she, or you (você), including ela makes it explicit that the subject is she.

No is a contraction of:

• em = in / at
• o = the

So:

• em + o = no

That means no tribunal literally comes from in the court / at the courthouse / in the tribunal.

This kind of contraction is extremely common in Portuguese:

• em + a = na
• em + os = nos
• em + as = nas

So Ela trabalha no tribunal uses the normal contracted form.

Portuguese often uses definite articles more naturally than English does.

Here, tribunal is treated as a specific place or institution, so the article appears:

• no tribunal = in/at the court

In English, you might sometimes say she works in court or she works at court in a more abstract sense, but Portuguese commonly uses the article here.

Tribunal usually refers to a court or judicial body. Depending on context, it can suggest:

• a court of law
• a court building
• a higher court / tribunal

So Ela trabalha no tribunal usually means she works in the judicial system or at a court.

It is related to the English word tribunal, but in everyday Portuguese it can often correspond to what English speakers would simply call court.

It usually means works in the present tense, and very often it expresses a habitual or general fact:

• Ela trabalha no tribunal. = She works at the court / She works in the court system.

It does not usually mean she is working right now at this moment. For that ongoing meaning, Portuguese often uses:

• Ela está trabalhando no tribunal. = She is working at the court.

So the simple present in Portuguese often covers the idea of a regular job or routine.

In Brazilian Portuguese, trabalha is approximately pronounced like:

• trah-BAHL-yah

A few important points:

• The stress is on ba: traBALha
• lh is a special Portuguese sound, similar to the lli in some pronunciations of million, though not exactly the same
• The final a is a light ah sound

So it is not pronounced like English trab-al-ha with a separate l sound.

A natural Brazilian Portuguese pronunciation is roughly:

• EH-lah tra-BAHL-yah no tree-boo-NAU

A few notes:

• Ela = EH-lah
• trabalha has stress on bal
• no sounds like noh
• tribunal is stressed on the last syllable: tri-bu-NAL
• In many Brazilian accents, the final l in tribunal sounds like a w-like sound, so it can sound like tribunau

Grammatically, em tribunal can exist in some contexts, but no tribunal is the normal and most natural choice here.

Why? Because Portuguese usually uses the article with this kind of place:

• no tribunal = at the court / in the court

Using em tribunal without the article would sound less natural in this sentence unless there were a very specific stylistic or contextual reason.

The verb would change depending on the subject:

• Eu trabalho no tribunal. = I work at the court.
• Ele trabalha no tribunal. = He works at the court.
• Você trabalha no tribunal. = You work at the court.
• Nós trabalhamos no tribunal. = We work at the court.
• Elas trabalham no tribunal. = They work at the court.

So in your original sentence, trabalha matches ela.

It can correspond to either, depending on context.

Portuguese em often covers both English in and at when talking about location. So:

• no tribunal can mean in the court
• or at the court

In many real situations, English would more naturally say She works at the courthouse or She works in the court system, depending on what exactly is meant. Portuguese leaves that broader and lets context clarify it.