Cada condômino usa uma procuração.

Because cada is grammatically singular in Portuguese. Even though it refers to multiple people one by one, the verb agrees in the singular:

• Cada aluno estuda.
• Cada pessoa tem uma opinião.
• Cada condômino usa uma procuração.

So usa is the correct form.

With cada, Portuguese normally uses a singular noun:

• cada aluno
• cada morador
• cada condômino

This is just like English each resident, not each residents.

If you wanted a plural structure, you would usually change the sentence pattern, for example:

• Todos os condôminos usam procuração.

That has a slightly different feel, because it is more collective than distributive.

Because cada already functions as the determiner for the noun. So Portuguese says:

• cada condômino

not:

• cada o condômino

This is a normal pattern. Compare:

• cada pessoa
• cada casa
• cada funcionário

Usually cada is closest to each, because it highlights the individuals one by one.

So Cada condômino usa uma procuração has a distributive sense: each condo owner uses one.

In many contexts, English might still translate it as every condo owner uses a proxy/power of attorney, but each is often the more precise match.

Condômino usually means a person who owns a unit in a condominium, or more broadly a co-owner in a shared property arrangement.

In Brazilian Portuguese, it is a fairly formal or administrative word. In everyday speech, people may sometimes use something more general depending on context, such as:

• morador do condomínio = resident of the condominium
• proprietário = owner

The feminine form is condômina.

Procuração is a formal authorization document that gives someone the power to act on another person’s behalf.

Depending on context, it can correspond to:

• power of attorney
• proxy
• proxy authorization
• authorization form

In a condominium meeting context, procuração often means a proxy document allowing someone else to represent the owner at the meeting.

Uma is the indefinite article, meaning a/an.

So uma procuração means a power of attorney / a proxy document.

It shows that the sentence is talking about one instance of that document, not a specific previously identified one.

Compare:

• usa uma procuração = uses a proxy / a power of attorney
• usa a procuração = uses the specific proxy / the already-mentioned document

Yes. That would be grammatical.

The difference is mostly style:

• usa = more common, everyday, direct
• utiliza = a bit more formal or bureaucratic

So both work, but usa sounds very natural.

A rough Brazilian Portuguese guide would be:

• condômino: con-DÔ-mi-no
• procuração: pro-cu-ra-SÃO

A few useful details:

• The stress in condômino falls on dô.
• The ç in procuração sounds like s.
• The ending -ão is nasal and stressed.
• usa is pronounced with a z sound: U-za.