Todos querem justiça.

Because todos is the plural form.

• todo usually means every or whole/entire, and it often goes with a singular noun:

  • todo o dia = all day / the whole day
  • todo livro is not the normal way to say every book in standard Portuguese; you would usually say cada livro or todos os livros, depending on the meaning.

• todos on its own can work as a pronoun meaning everyone or all (people).

So in Todos querem justiça, todos is standing alone and means everyone.

Because the subject todos is third person plural, so the verb has to agree with it.

The verb is querer (to want), in the present tense:

• eu quero
• tu queres
• ele/ela quer
• nós queremos
• vocês/eles/elas querem

Since todos refers to more than one person grammatically, Portuguese uses querem.

Yes. This is a common thing for English speakers to notice.

Even though todos can be translated as everyone, grammatically it is still plural in Portuguese. It literally behaves more like all people.

That is why the verb is plural:

• Todos querem... not
• Todos quer...

Because justiça here is being used as an abstract noun in a general sense.

Portuguese often leaves out the article with abstract ideas when speaking generally:

• Querem justiça = they want justice
• Precisamos de paz = we need peace
• Ela procura felicidade = she is looking for happiness

If you add an article, the meaning may become more specific, stylistic, or context-dependent:

• a justiça can mean justice as a concept in a more definite way, or even the justice system / the courts, depending on context.

So Todos querem justiça sounds natural for a broad, general statement.

Yes, todos is the masculine plural form.

Portuguese uses:

• todos for a group of men, a mixed group, or a group of unspecified gender
• todas for a group of only women

So:

• Todos querem justiça.
• Todas querem justiça.

For a general statement like everyone wants justice, todos is the normal default form.

Yes, but it changes the emphasis slightly.

• Todos querem justiça = everyone wants justice
• Eles querem justiça = they want justice

So eles just means they, while todos means all of them / everyone.

Also, Portuguese often omits subject pronouns when they are not needed. In this sentence, the subject is already clearly expressed by todos, so adding eles would usually be unnecessary.

This is a very common question.

• todos = all / everyone / all of them
  Used with countable plural things or people
• tudo = everything / all
  Used for things in a more general, non-countable sense

Examples:

• Todos querem justiça. = everyone wants justice
• Todos os livros estão aqui. = all the books are here
• Tudo está bem. = everything is fine
• Eu vi tudo. = I saw everything

So you cannot say Tudo querem justiça.

Yes. A very common alternative is:

• Toda a gente quer justiça.

This is extremely natural in Portugal and means roughly the same thing.

There is a small grammar difference:

• Todos querem... → plural verb
• Toda a gente quer... → singular verb

That is because gente is grammatically singular, even though it refers to many people.

Both are correct, but toda a gente is especially common in everyday European Portuguese.

A simple learner-friendly approximation is:

• TO-dush KÉ-rem zhoo-STEE-sya

A few useful points:

• Final -os in European Portuguese often sounds more like -ush than a clear -os
• qu in querem sounds like k
• j in justiça sounds like the s in measure or the zh sound
• The ti in justiça sounds like tee, not like English sh
• European Portuguese often reduces unstressed vowels, so the sentence may sound more compressed than a learner expects

You do not need perfect pronunciation right away, but it helps to know that European Portuguese is usually less open and less clearly syllabic than Brazilian Portuguese.

Yes, depending on context.

• In Todos querem justiça, it most naturally means justice as an idea: fairness, what is right.
• In other contexts, a Justiça can refer to the courts, the legal system, or the judicial authorities.

For example:

• A Justiça decidiu o caso. = The courts / the justice system decided the case.

So context matters, but in your sentence the abstract meaning is the natural one.

The normal, neutral order is:

• Todos
  • querem
    • justiça

That is the standard subject + verb + object pattern.

Portuguese can change word order for emphasis, style, or rhetoric, but the basic sentence is most naturally said this way.

For example, something like Justiça, todos querem is possible in a dramatic or literary context, but it is not the neutral everyday order.

So for ordinary use, Todos querem justiça is exactly what learners should aim for.