Paulo aceitou adiar a reunião.

Aceitou is the 3rd person singular preterite of aceitar.

So it means that Paulo’s act of agreeing/accepting happened as a completed action in the past.

• eu aceitei = I agreed / accepted
• você / ele / ela aceitou = you / he / she agreed / accepted
• Paulo aceitou = Paulo agreed / accepted

In Brazilian Portuguese, this tense is very commonly used for single completed past events.

Because aceitar + infinitive often means to agree to do something.

So:

• Paulo aceitou adiar a reunião = Paulo agreed to postpone the meeting

But when aceitar is followed by a noun, it often means accept in the more direct sense:

• Paulo aceitou a proposta. = Paulo accepted the proposal.
• Paulo aceitou o convite. = Paulo accepted the invitation.

So the structure helps determine the meaning.

Because it comes after the conjugated verb aceitou.

Portuguese often uses this pattern:

• verb + infinitive

Here, aceitou is the conjugated verb, and adiar stays in the infinitive because it expresses the action Paulo agreed to do.

Compare:

• Paulo quer adiar a reunião. = Paulo wants to postpone the meeting.
• Paulo decidiu adiar a reunião. = Paulo decided to postpone the meeting.
• Paulo aceitou adiar a reunião. = Paulo agreed to postpone the meeting.

This is similar to English agreed to postpone, where postpone is not conjugated.

Because a reunião means the meeting.

• reunião = meeting
• a reunião = the meeting

Also, reunião is a feminine singular noun, so the definite article is a.

This a is just the article, not the preposition to.

Portuguese usually uses articles more often than English does, so a reunião sounds very natural here.

No. After aceitar, you can directly use the infinitive.

So this is correct:

• Paulo aceitou adiar a reunião.

These would be wrong in this structure:

• Paulo aceitou em adiar a reunião.
• Paulo aceitou para adiar a reunião.

If you want a different structure, you could use a clause instead:

• Paulo aceitou que a reunião fosse adiada.
  = Paulo agreed that the meeting should be postponed.

But in the original sentence, aceitou + infinitive is the normal pattern.

Usually, yes: the sentence most naturally suggests that Paulo agreed to the action of postponing the meeting.

In other words, Paulo is the subject of aceitou and is also understood as the person involved in adiar.

If you want to make a different idea clearer, Portuguese often changes the structure:

• Paulo aceitou o adiamento da reunião.
  = Paulo accepted the postponement of the meeting.

That version focuses more on Paulo accepting the postponement as a fact or decision, not necessarily being the one carrying it out.

Not exactly.

• adiar = to postpone, to put off to a later time/date
• atrasar = to delay, to make late, to run behind

So:

• adiar a reunião = postpone the meeting
• atrasar a reunião can mean delay the meeting, make it start late, or cause it to run late

Another related verb is postergar, which also means to postpone, but it often sounds more formal or less common in everyday speech than adiar.

A rough Brazilian Portuguese pronunciation guide:

• aceitou ≈ ah-say-TOH
• adiar ≈ ah-jee-AR in many Brazilian accents
• reunião ≈ heh-oo-nee-OWN, with a nasal ending on -ão

A few helpful notes:

• aceitou is stressed on the last syllable: -tou
• adiar is also stressed on the last syllable: -ar
• reunião is stressed on -ão
• The r at the beginning of reunião is usually pronounced like a Brazilian Portuguese h-like sound
• The ending -ão is nasal, which is very important in Portuguese pronunciation

The standard form is:

• Paulo aceitou adiá-la.

Here is what happens:

• a reunião is a feminine singular direct object
• the direct object pronoun is a
• after an infinitive ending in -r, Portuguese often:
  • drops the -r
  • attaches -la
  • adds an accent if needed

So:

• adiar + a → adiá-la

This kind of object pronoun placement is very common in more careful or written Portuguese. In everyday spoken Brazilian Portuguese, many speakers avoid this structure and may rephrase the sentence instead.

Yes, but the original order is the most neutral and natural:

• Paulo aceitou adiar a reunião.

That is the normal subject + verb + complement order.

You can change the order for emphasis, but it becomes less neutral:

• A reunião, Paulo aceitou adiar.

This sounds more marked, as if you are specifically emphasizing the meeting.

So for learners, the original version is the best default pattern to use.