Antes de sair, ela pega o capacete e verifica o freio da moto.

Because antes normally takes the preposition de when it is followed by a verb.

• antes de sair = before leaving / before she leaves
• antes da aula = before class

So in Portuguese, antes de + infinitive is the standard pattern.

After antes de, Portuguese usually uses the infinitive form of the verb when the subject is general or understood from context.

• Antes de sair, ela... = Before leaving, she...
• Antes de dormir, eu leio. = Before sleeping / before I go to sleep, I read.

If you want to make the subject especially explicit, Portuguese can also use the personal infinitive in some cases:

• Antes de sairmos, fechamos a porta. = Before we leave, we close the door.

In your sentence, plain sair works because the subject is easy to understand from the sentence.

Pega is from the verb pegar, which has several meanings depending on context. Here it means something like:

• takes
• picks up
• gets

So ela pega o capacete is naturally understood as she picks up / takes the helmet.

It does not necessarily mean she is stealing it or catching it; context decides the best English translation.

In Portuguese, the simple present is often used for:

• actions happening now
• habitual actions
• routines
• general descriptions

So ela pega and verifica can describe what she typically does before leaving.

This is very natural in Portuguese, just as in English you can say:

• Before leaving, she picks up the helmet and checks the motorcycle brake.

Yes, it could be omitted.

Portuguese often drops subject pronouns because the verb form already shows the person:

• ela pega = she takes
• pega can also mean she takes, depending on context

So you could say:

• Antes de sair, pega o capacete e verifica o freio da moto.

However, including ela can help with clarity, emphasis, or smoother style. In learning materials, pronouns are often included to make the subject obvious.

Portuguese uses definite articles (o, a, os, as) more often than English does.

So Portuguese naturally says:

• o capacete = the helmet
• o freio = the brake

Even where English might sometimes say her helmet or just helmet in a certain context, Portuguese often prefers the article if the object is specific and understood.

In this sentence, it refers to the specific helmet and the specific brake associated with the situation.

Da is a contraction of:

• de + a = da

So:

• o freio da moto = the brake of the motorcycle / the motorcycle’s brake

This is one of the most common contractions in Portuguese:

• do = de + o
• da = de + a
• dos = de + os
• das = de + as

Since moto is feminine (a moto), the sentence uses da.

Because moto here is a specific noun phrase with an article: a moto.

• de moto usually means by motorcycle or on a motorcycle
• da moto means of the motorcycle

Compare:

• Ela vai de moto. = She goes by motorcycle.
• O freio da moto = The motorcycle’s brake.

So the contraction da is required because the meaning is possession/association, not means of transportation.

Good question. Grammatically, o freio da moto is singular, and that is perfectly normal.

In real life, a motorcycle may have front and rear brakes, but the singular can be used:

• to refer to the braking system in a general way
• to mention the brake as a relevant mechanical part
• because the sentence is simplified and not technically specific

If someone wanted to be more precise, they could say:

• os freios da moto = the brakes of the motorcycle

But the singular is still very natural in everyday Portuguese.

Yes.

• moto = motorcycle / bike
• motocicleta = motorcycle

Moto is the much more common everyday word in Brazilian Portuguese. It is informal but completely standard in normal speech and writing.

So da moto sounds very natural.

All of these can mean something like checks, but they have slightly different flavors.

• verifica — a bit more neutral or formal; verifies/checks
• confere — very common in everyday speech; checks/confirms
• checa — also common, influenced by English check; a bit more colloquial in some contexts

So:

• verifica o freio da moto sounds natural and slightly more careful or formal
• confere o freio da moto sounds everyday and conversational
• checa o freio da moto also works in many contexts

Yes, that version is also correct.

Both are natural:

• Antes de sair, ela pega o capacete e verifica o freio da moto.
• Ela pega o capacete e verifica o freio da moto antes de sair.

The difference is mainly emphasis:

• Antes de sair, ... puts focus on the time sequence first
• Ela pega... antes de sair states the actions first and adds the time expression afterward

Portuguese is flexible here.

In Brazilian Portuguese, pega is roughly pronounced PEH-gah.

A few helpful points:

• e in pega is usually an open e, like eh
• g before a is a hard g, as in go
• the final a is an unstressed a, sounding like ah but lighter

So a rough guide is:

• pega ≈ PEH-gah

Not like English peg-a with an English g plus a strong schwa pattern.

For Brazilian Portuguese, capacete is the normal word for helmet.

It can be used for:

• motorcycle helmets
• construction helmets
• protective helmets in general

If context matters, you can be more specific:

• capacete de moto = motorcycle helmet
• capacete de segurança = safety helmet

In your sentence, just o capacete is enough because the motorcycle context already makes it clear.