Vou escrever o horário da reunião na minha agenda agora.

Vou escrever is the very common ir + infinitive future in Brazilian Portuguese. It works a lot like I’m going to write in English.

So:

• Vou escrever = I’m going to write
• Escreverei = I will write

Both are correct, but in everyday Brazilian Portuguese, vou escrever sounds much more natural in most conversations. The simple future (escreverei) is more formal, less common in speech, and can sound a bit stiff in many situations.

Vou is the eu form of the verb ir, which means to go.

• eu vou = I go / I am going

But in this sentence, vou is not about physically going somewhere. It is helping form the near future:

• vou escrever = I am going to write

So vou here is part of a future structure, not a literal movement verb.

Portuguese often leaves out subject pronouns when the verb form already makes the subject clear.

• Vou escrever already shows that the subject is I, because vou is the eu form.

So both are possible:

• Vou escrever o horário da reunião na minha agenda agora.
• Eu vou escrever o horário da reunião na minha agenda agora.

The version without eu is very natural. Adding eu can give emphasis or contrast.

Not exactly.

• hora usually means hour or time in a general sense
• horário often means a scheduled time, time slot, or schedule-related time

In this sentence, o horário da reunião means the time of the meeting or the scheduled meeting time.

So horário fits well because this is about an appointment or scheduled event, not just time in a broad sense.

Da is a contraction of:

• de + a = da

Here, reunião is being treated as a specific meeting:

• o horário da reunião = the time of the meeting

If you said de reunião, that would usually sound incomplete or would suggest a more general meaning, not a specific meeting. In this sentence, da reunião is the natural form because we are talking about a particular meeting.

Na is a contraction of:

• em + a = na

So:

• na minha agenda = in my agenda/planner

Portuguese uses these contractions very often, and they are required in normal usage.

A related point: agenda in Brazilian Portuguese usually means a planner, appointment book, or sometimes a calendar/schedule book. It usually does not mean the agenda for a meeting the way it often does in English.

Not usually.

In Brazilian Portuguese, agenda most often means:

• a planner
• a diary
• an appointment book
• a personal schedule book

So in this sentence, minha agenda means something like my planner or my calendar book.

If an English speaker sees agenda, they may think of a list of topics for a meeting, but that is not the most common meaning here.

Both can be correct.

Brazilian Portuguese often allows possessives with or without the definite article:

• minha agenda
• a minha agenda

Both mean my planner/agenda.

In Brazil, dropping the article is very common, especially in everyday speech. In some contexts, using the article can sound a bit more specific or slightly more formal, but both are natural.

So na minha agenda is completely normal.

Portuguese uses definite articles more often than English does.

• o horário = the time

Even when English might say just meeting time or something shorter, Portuguese often prefers an article:

• Vou escrever o horário da reunião...

That sounds natural because it refers to a specific piece of information: the meeting’s time.

Yes. Portuguese word order is flexible, and agora can appear in different positions.

For example:

• Vou escrever o horário da reunião na minha agenda agora.
• Agora vou escrever o horário da reunião na minha agenda.
• Vou agora escrever o horário da reunião na minha agenda.

All of these are possible. The most natural choice depends on emphasis:

• agora at the end can feel like right now
• agora at the beginning can emphasize now as a contrast with before or later

The original sentence sounds very natural.

Yes, very naturally.

• escrever = to write
• anotar = to write down / to note down

So:

• Vou escrever o horário da reunião na minha agenda agora.
• Vou anotar o horário da reunião na minha agenda agora.

Both are correct, but anotar may sound even more natural if the idea is to jot down the meeting time in your planner.

Usually, yes.

Using a reunião inside da reunião suggests a specific meeting, not just any meeting.

So the sentence usually implies something like:

• the meeting we already know about
• that meeting

If you wanted a more general meaning, the sentence would probably be phrased differently.

The original sentence is already natural. But in everyday speech, Brazilians might also say:

• Vou anotar o horário da reunião na minha agenda agora.
• Vou colocar o horário da reunião na minha agenda agora.

These can feel a little more conversational depending on the context:

• anotar = write down
• colocar = put/add

Still, vou escrever o horário da reunião na minha agenda agora is perfectly good Portuguese.