A professora pediu-nos que escrevêssemos o título em maiúsculas e o resto em minúsculas.

Pediu-nos breaks down as:

• pediu = asked / requested
• -nos = us

So A professora pediu-nos... means The teacher asked us...

Also, pediu is the preterite (simple past) of pedir, so it refers to a completed past action: she asked us.

Because in European Portuguese, unstressed object pronouns often come after the verb in an affirmative main clause. This is called enclisis.

So in Portugal, pediu-nos is the normal standard pattern.

Compare:

• A professora pediu-nos... = standard European Portuguese
• A professora não nos pediu... = after não, the pronoun moves before the verb

A native English speaker may notice that Brazilian Portuguese more often uses nos pediu, but for Portugal Portuguese, pediu-nos is the expected form here.

Portuguese often uses the structure:

pedir a alguém que + subjunctive

So:

• A professora pediu-nos que escrevêssemos...

This is the normal way to say the teacher asked us to write...

English uses asked us to write, with an infinitive. Portuguese usually prefers asked us that we write in structure, even though that literal translation sounds unnatural in English.

Because after pedir que, Portuguese normally uses the subjunctive.

Here the main verb is in the past:

• pediu = asked

So the subordinate verb is usually put in the imperfect subjunctive:

• que escrevêssemos = that we write / to write, after a past verb of request

A useful comparison:

• A professora pede-nos que escrevamos... = present
• A professora pediu-nos que escrevêssemos... = past

Because escrevemos is the indicative, and this sentence needs the subjunctive.

After verbs of request, command, desire, recommendation, etc., Portuguese commonly uses the subjunctive:

• pedir que
• querer que
• recomendar que
• ordenar que

So:

• pediu-nos que escrevêssemos = correct
• pediu-nos que escrevemos = not correct here

Because the teacher asked us to do the writing.

The -nos in pediu-nos tells you who was asked, and that same group becomes the understood subject of escrevêssemos:

• she asked us
• that we should write

Portuguese usually leaves out the subject pronoun when the verb ending already makes it clear, so there is no need to say nós escrevêssemos.

Portuguese uses definite articles more often than English.

So A professora is perfectly normal for:

• the teacher
• sometimes, depending on context, effectively our/the teacher

English often leaves the article out in places where Portuguese keeps it.

The same thing happens later with:

• o título = the title
• o resto = the rest

O resto means the rest — in this sentence, everything apart from the title.

So:

• o título em maiúsculas = the title in uppercase
• o resto em minúsculas = the rest in lowercase

It is a very common expression in Portuguese.

Because em is commonly used to describe the form, style, or format in which something is written.

So:

• em maiúsculas = in uppercase / in capital letters
• em minúsculas = in lowercase

You see the same pattern in other expressions:

• em itálico = in italics
• em negrito = in bold

They are understood as short for:

• letras maiúsculas
• letras minúsculas

Since letras is feminine plural, the adjectives are also feminine plural:

• maiúsculas
• minúsculas

Even though o título is singular, it is made up of several letters, so Portuguese naturally talks about writing it in uppercase letters.

Because Portuguese, like English, often omits repeated words when the meaning is already clear.

So:

• A professora pediu-nos que escrevêssemos o título em maiúsculas e o resto em minúsculas.

means the same as the fuller version:

• A professora pediu-nos que escrevêssemos o título em maiúsculas e escrevêssemos o resto em minúsculas.

The second version is grammatical, but it sounds heavier and less natural because the verb is already understood.

They mainly help show stress and sometimes vowel quality.

For example:

• título
• maiúsculas
• minúsculas

The acute accent shows which syllable is stressed.

In escrevêssemos, the ê also helps show the quality of the vowel, not just the stress.

For a learner, the most useful thing to remember is this: the accents are not optional spelling decorations — they are part of the correct written form and help you pronounce the word properly.