Minha tia deixou um recado dizendo que vai chegar depois da reunião.

Both are possible in Brazilian Portuguese.

• Minha tia = natural and common
• A minha tia = also natural, especially in spoken Brazilian Portuguese

Portuguese often allows a definite article before possessives, but it is not always required. In this sentence, leaving the article out sounds completely normal.

Deixou is the preterite form of deixar.

That means it describes a completed action in the past. Here, the aunt already left the message. In dictionary form, the verb is deixar.

• eu deixei
• você/ele/ela deixou
• nós deixamos

So Minha tia deixou... means the action of leaving the message is finished.

Here, deixar means something like to leave in the sense of to leave behind, to leave a note/message, or to pass along.

In other contexts, deixar can also mean:

• to let / allow
• to stop / quit
• to leave something somewhere

So the exact meaning depends on context. In this sentence, it means she left a message.

Recado means a message, note, or short message left for someone.

It often suggests something brief and practical, like:

• a message left with another person
• a note
• a quick message to pass on

Mensagem is also correct for message, but recado feels very common and everyday in this kind of sentence. Recado is especially natural when someone leaves information for another person.

Because um introduces the message as new information.

• um recado = a message
• o recado = the message

If the speaker and listener already knew which specific message they were talking about, o recado might be used. Here, the sentence is just introducing the idea that she left a message, so um recado is the natural choice.

Because Portuguese nouns have grammatical gender.

In this sentence:

• tia is feminine → minha tia
• recado is masculine → um recado
• reunião is feminine → da reunião

The words around the noun have to agree with its gender:

• minha agrees with tia
• um agrees with recado
• a is the feminine article inside da for reunião

This is something you usually learn noun by noun.

Dizendo is the gerund of dizer, and it works a lot like English saying.

So um recado dizendo que... means a message saying that...

It adds extra information about the content of the message. This is a very natural structure in Portuguese.

Because que introduces the content of what was said.

So:

• dizendo que vai chegar... = saying that she is going to arrive...

In English, that is sometimes omitted. In Portuguese, que is much more commonly kept in this kind of sentence. Saying dizendo vai chegar would be incorrect.

The subject is still minha tia.

Portuguese often omits subject pronouns when the meaning is clear from context. So instead of saying ela vai chegar, the sentence simply says vai chegar, and the listener understands that it refers to the aunt.

This is very common in Portuguese.

Both are correct, but vai chegar is much more common in everyday Brazilian Portuguese.

• vai chegar = very natural in speech
• chegará = more formal, more written, or more literary

This is the common ir + infinitive future structure:

• vai chegar
• vou sair
• vamos ver

So this sentence sounds very natural and conversational.

Because depois is followed by de in this structure:

• depois de

When de comes before the feminine article a, they contract:

• de + a = da

So:

• depois da reunião = after the meeting

This contraction is required here.

Because the sentence is referring to a specific meeting, not meetings in general.

• depois da reunião = after the meeting

The article makes it specific. Without that article, the phrase would not sound right in this context.

No, not explicitly.

Minha tia deixou um recado... only tells us that your aunt left a message. It does not directly say for me or for someone else.

If you want to say My aunt left me a message, you could say:

• Minha tia me deixou um recado
• Minha tia deixou um recado para mim

So the original sentence leaves the recipient unstated.

Yes, you might hear falando que in casual speech, but dizendo que is the better choice here.

Why?

• dizer is more directly connected to the content of a message
• falar is broader and means to speak / to talk

So deixou um recado dizendo que... sounds more precise and natural for a message.