A renda continua, ao passo que a renda extra muda.

Here, renda means income or earnings.

A learner should know that renda can have other meanings in Portuguese too, especially lace in clothing or fabric contexts. But in this sentence, because of renda extra, the financial meaning is the natural one.

So in this sentence:

• a renda = the income
• a renda extra = the extra income / side income

Portuguese uses definite articles much more often than English.

So a renda literally looks like the income, but depending on context it can also sound more general, like income as a concept.

This is very normal in Portuguese:

• A vida é curta. = Life is short.
• O dinheiro muda tudo. = Money changes everything.

So a renda continua does not necessarily mean one very specific income already mentioned before. It can also refer to income in a general or understood sense.

In Portuguese, adjectives usually come after the noun.

So:

• renda extra = extra income
• dinheiro extra = extra money
• trabalho extra = extra work

English often puts adjectives before the noun, but Portuguese usually places them after it.

Also, renda extra is a very common fixed expression in Brazilian Portuguese.

Continua is from the verb continuar, meaning to continue.

In this sentence, a renda continua can mean something like:

• the income continues
• the income keeps coming
• the income remains steady, depending on context

Portuguese sometimes leaves implied information unstated if it is easy to understand. So the idea may be that the main income is ongoing or stable, while the extra income changes.

Ao passo que is a connector meaning:

• whereas
• while
• in contrast
• as opposed to

It is used to compare two ideas, often with a contrast between them.

So the sentence structure is:

• A renda continua = one thing happens
• ao passo que a renda extra muda = but, by contrast, the extra income changes

It sounds a little more formal or written than very everyday speech.

Yes, but it sounds a bit more formal or careful than some other contrast expressions.

In everyday Brazilian Portuguese, people might more often say:

• enquanto = while / whereas
• mas = but
• já = often used contrastively in some contexts

For example, a more conversational version might be:

• A renda continua, mas a renda extra muda.

The original sentence is perfectly correct, but ao passo que has a slightly more polished or analytical tone.

Because a renda extra is the natural full noun phrase.

Portuguese often repeats the noun for clarity, especially when the second idea is meant to be clearly contrasted with the first.

• a renda = the income
• a renda extra = the extra income

Saying a extra by itself would usually sound incomplete or unnatural here, because extra is not normally used alone as a noun in this structure.

So the repetition helps keep the contrast clear and natural.

Both are in the present indicative.

• continua = continues
• muda = changes

This tense is often used in Portuguese, just like in English, for:

• general truths
• habitual situations
• ongoing states
• regular patterns

So the sentence presents a general contrast:

• the main income continues
• the extra income changes

Muda is the simple present and is the most straightforward choice for a general statement.

• muda = changes
• está mudando = is changing right now / in progress
• mudou = changed
• muda-se would be a different structure and would not fit naturally here

The sentence is not focusing on a change happening at this exact moment. It is expressing a general pattern or contrast, so muda works best.

Yes, depending on context, it can suggest that.

Literally, continuar means to continue, but in many real contexts it can imply:

• it keeps going
• it remains
• it stays as it is

So a renda continua could be understood as:

• the income continues
• the income remains stable
• the income is still there

The exact nuance depends on the larger context.

It is very normal and appropriate here.

Ao passo que connects two clauses:

• A renda continua
• a renda extra muda

Because the sentence is contrasting two complete ideas, the comma helps readability and sounds natural in writing.

In this kind of sentence, the comma is standard.

Yes, but you should be careful because English while can mean either:

• during the time that, or
• whereas / in contrast

Here the meaning is the contrastive one. So possible translations include:

• The income continues, while the extra income changes.
• The income continues, whereas the extra income changes.
• The income remains steady, while the extra income changes.

If you want the contrast to be very clear in English, whereas is often the closest match to ao passo que.