Eu sempre chego no horário para a aula.

Yes. In Brazilian Portuguese, subject pronouns are often omitted when the verb form already makes the subject clear.

• (Eu) sempre chego no horário para a aula.

Because chego clearly means I arrive, eu is optional here.

Including eu can add:

• emphasis
• contrast
• clarity in some contexts

So both are natural:

• Sempre chego no horário para a aula.
• Eu sempre chego no horário para a aula.

Chego is the 1st person singular present tense form of chegar (to arrive).

Conjugation in the present:

• eu chego = I arrive
• você/ele/ela chega = you/he/she arrives
• nós chegamos = we arrive
• vocês/eles/elas chegam = you/they arrive

In this sentence, the present tense is being used for a habitual action:

• Eu sempre chego... = I always arrive...

So it does not mean only I am arriving right now. It means this is something the speaker regularly does.

Sempre means always, and it commonly goes before the verb in Portuguese.

So:

• Eu sempre chego no horário... = the most neutral, common order

You may also hear or see:

• Eu chego sempre no horário...

That is possible, but eu sempre chego sounds more natural and standard in most everyday contexts.

A good rule for learners:

• adverbs like sempre, nunca, geralmente often go before the main verb

Examples:

• Eu sempre estudo de manhã.
• Ela nunca chega cedo.

No horário literally means in the time/schedule, but in natural English it means:

• on time
• at the scheduled time

It is made of:

• em
  • o horário → no horário

So no is a contraction:

• em + o = no

This is very common in Portuguese:

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

So no horário is an expression meaning at the proper/scheduled time.

Because Portuguese normally contracts certain prepositions with articles.

Here:

• em + o horário becomes no horário

You generally should not say em o horário in normal Portuguese.

Some common contractions:

• de + o = do
• de + a = da
• em + o = no
• em + a = na
• a + a = à

So no horário is the correct form.

These can overlap, but they are not exactly the same.

no horário

Usually means on time / at the scheduled time.

• Eu sempre chego no horário para a aula.
• I arrive when class is supposed to begin.

na hora

Can also mean on time, but often feels a bit more like right at the time or exactly then, depending on context.

• Ele chegou na hora da reunião.
• He arrived at the time of the meeting.

a tempo

Usually means in time, often with the idea of before it is too late.

• Cheguei a tempo de pegar o ônibus.
• I arrived in time to catch the bus.

So in your sentence, no horário is a very natural choice because it refers to arriving according to the class schedule.

Para a aula means for class.

It shows the purpose or event that the timing relates to:

• I always arrive on time for class.

This is very natural in Brazilian Portuguese.

It helps answer:

• On time for what?
• Para a aula.

You can think of it as:

• chegar no horário para [something]

Examples:

• Cheguei no horário para a reunião.

• I arrived on time for the meeting.

• Ela chegou no horário para o trabalho.
• She arrived on time for work.

Yes. In spoken Brazilian Portuguese, pra aula is extremely common.

• para a aula = more careful, full form
• pra aula = very common spoken contraction

So these are both natural:

• Eu sempre chego no horário para a aula.
• Eu sempre chego no horário pra aula.

In writing:

• para a aula is safer in formal contexts
• pra aula is common in informal writing, messages, dialogue, etc.

Usually, not in this sentence.

À aula would come from a + a aula, but that is not the most natural choice here.

Why? Because the sentence is not mainly expressing movement to a destination in the same way as:

• Vou à escola. = I go to school.

Instead, it is expressing being on time for the class/event:

• no horário para a aula

So para a aula is the natural expression here.

If you change the structure, you might say something like:

• Eu sempre chego à escola no horário.
• I always arrive at school on time.

But with aula, para a aula is much more natural in this exact sentence.

Portuguese uses articles more often than English does.

In no horário, the o is the definite article the, but in English we usually just say:

• on time

not

• on the time

So Portuguese and English do not always match word-for-word.

Portuguese:

• no horário

English:

• on time

This is a good reminder that it is better to learn expressions as chunks, not translate each word literally.

Good question. This sentence can be confusing because chegar and no horário involve different ideas.

1. With destinations

Traditionally, grammar books often prefer:

• chegar a

Example:

• Cheguei à escola.

But in Brazilian Portuguese, especially in everyday speech, people very often say:

• chegar em
• Cheguei na escola.

2. In this sentence

No horário is not a destination like school or home. It is a time-related expression meaning on time.

So here:

• chego no horário is a fixed, natural expression

This does not mean the same thing as chego em o horário in a destination sense. It is simply the idiomatic phrase arrive on time.

So you can remember:

• chegar no horário = to arrive on time

Yes. In Portuguese, the present tense is often used for habitual or repeated actions.

So:

• Eu sempre chego no horário para a aula.

means:

• I always arrive on time for class.
• I am someone who always arrives on time for class.

It is a general habit, not just something happening right now.

More examples:

• Eu estudo à noite. = I study at night.
• Ela trabalha de casa. = She works from home.
• Nós sempre almoçamos juntos. = We always have lunch together.

A little, yes, but some versions sound more natural than others.

Most natural:

• Eu sempre chego no horário para a aula.

Also possible:

• Sempre chego no horário para a aula.
• Eu chego sempre no horário para a aula.

Less natural or more marked:

• No horário, eu sempre chego para a aula.
• This sounds more emphasized or contrastive.

For a learner, the safest version is:

• Eu sempre chego no horário para a aula.

A broad Brazilian pronunciation would sound roughly like:

• eh-ooh SEM-pree SHEH-goo noo oh-RAH-ryoo PAH-rah ah OW-lah

A few helpful notes:

• eu often sounds like eh-ooh
• sempre often sounds like SEM-pri / SEM-pree
• chego begins with a sh-like sound in most of Brazil
• no horário links smoothly in speech
• para is often reduced in speech:
  • para a aula → pra aula

In natural speech, many Brazilians would say something close to:

• Eu sempre chego no horário pra aula.

Yes, absolutely. It is natural and correct.

In very casual speech, though, many people would be even more likely to say:

• Eu sempre chego no horário pra aula.

Both are normal:

• para a aula = slightly more careful/full
• pra aula = very common in conversation

So the sentence is completely natural, especially in a learning or neutral standard form.