A maioria contactou a empresa.

In Portuguese, a maioria usually takes the definite article a when it means the majority in a general or specific sense.

So:

• A maioria contactou a empresa. = The majority contacted the company.

Without the article, maioria is much less natural here. You do sometimes see it in other structures, but in a simple sentence like this, a maioria is the normal choice.

Grammatically, a maioria is singular.

The head noun is maioria, which is a singular feminine noun, even though it refers to many people. That is why it often behaves like English the majority: it refers to a group, but the grammar is singular.

That is why the sentence uses:

• A maioria contactou...

and not:

• A maioria contactaram...

in standard usage.

Because the subject is a maioria, and maioria is singular.

So the standard agreement is:

• A maioria contactou a empresa.

This is very common with collective nouns in Portuguese. Even though many people are involved, the grammar follows the singular noun maioria.

You may sometimes hear plural agreement in less careful or more meaning-based speech, especially when the idea of the individual people is being emphasized, but the safest standard choice here is singular.

Contactou is the pretérito perfeito do indicativo.

In English, that often corresponds to the simple past:

• contactou = contacted

It refers to a completed action in the past.

The infinitive is contactar:

• eu contactei
• tu contactaste
• ele/ela/você contactou
• nós contactámos
• vós contactastes
• eles/elas/vocês contactaram

So in this sentence, contactou agrees with the singular subject a maioria.

Yes. In European Portuguese, contactar is the normal and standard verb.

So these are natural in Portugal:

• contactar alguém
• contactou a empresa
• vou contactar o cliente

A useful Portugal/Brazil note:

• In Portugal, contacto and contactar are standard.
• In Brazil, you will often see contato and contatar instead.

So this sentence is very naturally European Portuguese.

Because contactar is normally a direct transitive verb in Portuguese.

So you say:

• contactar a empresa
• contactar o diretor
• contactar os clientes

There is no preposition before the object, so there is no contraction like à.

Compare:

• contactou a empresa = contacted the company

not:

• contactou à empresa

That would be incorrect in standard Portuguese.

This a is the definite article meaning the.

• a empresa = the company

So the sentence has two different a words:

• A maioria → the majority
• a empresa → the company

They are both feminine singular definite articles, because both maioria and empresa are feminine singular nouns.

Yes, absolutely.

That version is often clearer because it explicitly says who makes up the majority:

• A maioria das pessoas contactou a empresa.
  = Most of the people contacted the company.

In your original sentence, a maioria stands on its own, and the listener understands the rest from context. So:

• A maioria contactou a empresa.

is fine when it is already clear the majority of whom you are talking about.

Yes. A maior parte is another very common way to express most or the greater part.

So these can be similar:

• A maioria contactou a empresa.
• A maior parte contactou a empresa.

In many contexts, both are natural.
Very roughly:

• a maioria can sound a bit more statistical or formal
• a maior parte can feel slightly more everyday

But both are common and correct.

Sometimes, yes, but the standard rule is still singular agreement.

Standard and safest:

• A maioria contactou a empresa.

You may sometimes come across plural agreement, especially when a plural complement appears and the speaker is thinking more about the people than about the collective noun:

• A maioria dos alunos contactou a empresa. ← standard
• A maioria dos alunos contactaram a empresa. ← sometimes heard, but less standard

For a learner, the best rule is:

• with a maioria, use a singular verb

In European Portuguese, contactou is pronounced with the stress on the last syllable:

• con-tac-TOU

A rough English-friendly guide would be:

• con-tac-TOH

A few useful points:

• the final -ou sounds like oh
• the ct cluster is kept in European Portuguese
• this matches the spelling contactar, contacto

That is another feature that differs from Brazilian forms like contato.

Yes, but the original order is the most neutral:

• A maioria contactou a empresa.

You could change the structure for emphasis or style, for example:

• Foi a maioria que contactou a empresa.
  = It was the majority who contacted the company.

Or in the passive:

• A empresa foi contactada pela maioria.
  = The company was contacted by the majority.

But if you just want the plain, natural statement, the original sentence is the best choice.

It is basically neutral and works well in both spoken and written European Portuguese.

• a maioria sounds normal and standard
• contactar is also standard and common in Portugal

So the sentence would fit well in:

• reports
• emails
• news-style writing
• everyday conversation

It does not sound especially slangy or especially literary.