O endereço mudou, de modo que atualizei o requerimento.

Here de modo que means so, therefore, or as a result.

In this sentence, it connects the two ideas like this:

• O endereço mudou = the address changed
• de modo que atualizei o requerimento = so I updated the application/form

So it introduces a consequence.

A very natural English translation would be:

• The address changed, so I updated the application.

Depending on context, de modo que can also mean something closer to in such a way that, but in your sentence the consequence meaning is the important one.

Both verbs are in the pretérito perfeito, which is the normal Portuguese tense for completed past actions.

• mudou = changed
• atualizei = I updated

The sentence describes two completed events:

1. The address changed.
2. Because of that, I updated the application.

So Portuguese uses the simple past here, just as English often does.

Verb breakdown:

• mudar → mudou = it/he/she changed
• atualizar → atualizei = I updated

Portuguese often omits the subject pronoun when the verb ending already makes the subject clear.

• atualizei clearly means I updated
• so eu is optional

Both are possible:

• atualizei o requerimento
• eu atualizei o requerimento

The version without eu is very normal and natural.

Portuguese does this much more than English does, because verb endings usually show who the subject is.

Portuguese uses definite articles more often than English.

So where English might say:

• the address
• the application

Portuguese also says:

• o endereço
• o requerimento

In this sentence, both refer to specific things already understood in context:

• the address in question
• the specific application/document that needed updating

A native English speaker sometimes wants to drop the article, but in normal Portuguese these articles sound natural and expected.

Requerimento is a fairly formal word. Depending on context, it can mean:

• application
• request
• petition
• formal form/document

In Brazilian Portuguese, it often refers to an official written request or an administrative document.

So in your sentence, atualizei o requerimento likely means something like:

• I updated the application
• I updated the form
• I updated the request document

It is more formal than a casual word like pedido.

Yes. In everyday Brazilian Portuguese, there are several simpler or more common alternatives, depending on tone.

Possible replacements:

• então = so, then
• por isso = because of that, therefore
• assim = thus, so
• de forma que = similar to de modo que

Examples:

• O endereço mudou, então atualizei o requerimento.
• O endereço mudou, por isso atualizei o requerimento.

These sound a bit more conversational than de modo que, which is slightly more formal or written.

The comma separates the two clauses:

• O endereço mudou
• de modo que atualizei o requerimento

Since de modo que introduces the result or consequence of the first clause, a comma is natural here.

In written Portuguese, this punctuation helps show the structure clearly:

• first, the cause or situation
• then, the result

So the comma is not random; it marks the relationship between the two parts of the sentence.

Mudou here is active/intransitive and means changed.

• O endereço mudou = The address changed

This means the address itself became different.

By contrast:

• O endereço foi mudado = The address was changed

That is passive and suggests that someone changed it.

Both are possible in Portuguese, but they are not exactly the same:

• mudou focuses on the fact that it changed
• foi mudado focuses more on an action done by someone

In your sentence, mudou sounds more natural and less heavy.

O endereço mudou is the most neutral, standard word order:

• subject + verb

Portuguese can sometimes use:

• Mudou o endereço

But that usually sounds more marked, more literary, or more context-dependent. It may suggest something like the address changed with special focus on the event itself.

For a learner, the safest pattern is:

• O endereço mudou

That is the normal, straightforward way to say it.

It depends on the meaning.

In your sentence, de modo que expresses a real result/consequence, so it takes the indicative:

• O endereço mudou, de modo que atualizei o requerimento.

Here the update really happened.

But in some contexts, expressions like de modo que or especially de modo a que can introduce a purpose or intended result, and then the subjunctive may appear.

For your sentence, though, the important point is:

• real consequence → indicative
• atualizei is therefore perfectly normal

Yes. Endereço most commonly means address, especially a street or mailing address, but it can also mean:

• web address / URL
• location or direction information
• figuratively, a destination or target in some contexts

In this sentence, the most likely meaning is a physical or official address, especially because it is connected to updating a requerimento, which sounds like paperwork.

So a learner should understand endereço broadly as address, with the exact type depending on context.

Yes, atualizar is a very good verb here.

It means:

• to update
• to bring up to date
• to revise with new information

So:

• atualizei o requerimento = I updated the application/form

That suggests the document already existed, and then new information was entered because something changed.

This is different from verbs like:

• preencher = to fill out
• corrigir = to correct
• alterar = to change/modify

So atualizar is especially appropriate when information becomes outdated and needs to be brought up to date.

A rough pronunciation guide for Brazilian Portuguese would be:

• endereço ≈ en-de-RE-soo or en-de-RE-su
• mudou ≈ moo-DOH
• requerimento ≈ he-keh-ree-MEN-too in many Brazilian accents, because the r at the start of the word sounds like an English h

A few helpful notes:

• ç in endereço sounds like s
• final o in many Brazilian accents sounds close to oo
• the stressed syllable in requerimento is men

So the stress pattern is:

• en-de-RE-ço
• mu-DOU
• re-que-ri-MEN-to

It sounds neutral to somewhat formal.

Why?

• de modo que is a bit more formal than everyday então
• requerimento is a fairly formal word
• the structure is polished and suitable for writing

A more casual version might be:

• O endereço mudou, então atualizei o formulário.
• O endereço mudou, por isso atualizei o pedido.

So your original sentence would fit well in:

• emails
• official explanations
• reports
• administrative writing

It is correct and natural, just not especially conversational.