O contacto da empresa mudou.

In this sentence, contacto usually means a contact detail or contact point for the company, such as:

• a phone number
• an email address
• a person to contact
• general contact information

The exact meaning depends on context. If you saw this on a website or in an email, it often means the company’s contact details have changed.

Because contacto is a masculine singular noun in Portuguese.

So it takes:

• o contacto = the contact

If it were feminine, it would take a, but it is not.

A good thing to memorize is the noun together with its article:

• o contacto
• a empresa

Da is a contraction of:

• de + a = da

Here:

• empresa is feminine, so it uses a
• de a empresa becomes da empresa

So:

• o contacto da empresa = the company’s contact / the contact of the company

This is a very common structure in Portuguese for showing possession or association.

Portuguese normally does not show possession with an apostrophe like English does.

Instead, it often uses:

• de = of

So English:

• the company’s contact

becomes Portuguese:

• o contacto da empresa
• literally: the contact of the company

This is one of the most common ways Portuguese expresses possession.

Mudou is the 3rd person singular of the verb mudar in the pretérito perfeito.

• mudar = to change
• mudou = changed / has changed

It matches the subject o contacto, which is singular:

• O contacto ... mudou.
• The contact ... changed / has changed.

Because the Portuguese pretérito perfeito often covers both ideas that English separates into:

• changed
• has changed

Which English version sounds best depends on context.

So O contacto da empresa mudou can naturally mean:

• The company’s contact changed
• The company’s contact has changed

In everyday usage, the second is often the more natural English translation.

Here mudar is being used intransitively, meaning the thing itself changed.

• O contacto da empresa mudou.
• The company’s contact changed.

Portuguese can also use mudar transitively:

• A empresa mudou o contacto.
• The company changed the contact.

So the difference is:

• o contacto mudou = the contact changed
• a empresa mudou o contacto = the company changed the contact

Yes. That is also correct, but it means something slightly different in structure.

• O contacto da empresa mudou.
  Focus: the contact changed.

• A empresa mudou o contacto.
  Focus: the company changed the contact.

In many contexts, both could fit, but the original sentence presents the contact as the grammatical subject.

This is the normal, neutral Portuguese word order:

• subject + verb

So:

• O contacto da empresa = subject
• mudou = verb

Portuguese can sometimes change word order for style or emphasis:

• Mudou o contacto da empresa.

That can sound more marked, more journalistic, or more context-dependent. For a basic statement, O contacto da empresa mudou is the most straightforward version.

It can mean both, depending on context.

It may refer to:

• a contact person
• a useful professional connection
• contact details such as email or phone number

In this sentence, many learners will first understand it as contact details, but context is what decides the exact meaning.

For example:

• On a website: probably contact information
• In business networking: possibly the company’s contact person

Both empresa and companhia can relate to the idea of a company, but empresa is the most common neutral word for a business or company.

• empresa = company, business, firm

Companhia can also mean company, but it is used in more specific contexts and also has other meanings, such as companionship or company in the sense of being with someone.

So in a general sentence like this, empresa is the most natural choice.

Yes, this is the usual European Portuguese spelling.

In Portugal:

• contacto

In Brazil, you will usually see:

• contato

This is a well-known European/Brazilian difference. If you are learning Portuguese from Portugal, contacto is the form to learn.

Yes, in European Portuguese the c in contacto is pronounced, which is one reason the spelling keeps it.

Very roughly for an English speaker, it sounds something like:

• con-TAK-tu

A few helpful points:

• the stress is on tak
• the ct cluster is pronounced
• the final o in European Portuguese is usually reduced, not a strong English oh

And mudou is roughly:

• mu-DOH
  with the stress on the second syllable

Normally, no. In a full standard sentence, you would usually keep the definite article:

• O contacto da empresa mudou.

Portuguese uses articles more regularly than English in many situations. Leaving it out here would sound incomplete or unnatural unless it were part of a heading, note, or very abbreviated style.

For example, as a website heading, you might see something shorter, but as a normal sentence, o should stay.

Here are the base forms:

• o = the
• contacto = contact
• de
  • a → da = of the
• empresa = company
• mudou ← mudar = to change

So the key vocabulary items to learn are:

• o contacto
• a empresa
• mudar

Depending on context, natural English versions include:

• The company’s contact has changed.
• The company’s contact details have changed.
• The company contact changed.
• The contact for the company has changed.

If the context is a website, email footer, or customer information page, The company’s contact details have changed is often the most natural interpretation.