Eu vou falar com ele depois da reunião.

Vou falar is the very common ir + infinitive future in Brazilian Portuguese. It works a lot like going to + verb in English.

• Eu vou falar com ele = I’m going to talk to him
• Eu falarei com ele = I will talk to him

Both are correct, but in everyday spoken Brazilian Portuguese, vou falar is much more common and sounds more natural in conversation. Falarei is more formal and less frequent in speech.

You can absolutely omit Eu:

• Eu vou falar com ele depois da reunião
• Vou falar com ele depois da reunião

Both are correct.

Portuguese often drops subject pronouns when the verb already makes the subject clear. Since vou clearly shows I, Eu is optional here.

You might include Eu for:

• emphasis
• contrast
• clarity

For example:

• Eu vou falar com ele, não você.
  (I’m going to talk to him, not you.)

Because the verb falar usually takes the preposition com when you mean talk with / talk to someone.

• falar com alguém = to talk to/with someone

So:

• falar com ele = talk to him

You cannot normally say:

• falar ele ❌

That would be incorrect in this meaning.

Yes, but the meaning shifts slightly.

• falar com ele = talk with/to him
• falar para ele = often more like say/tell something to him or speak to him

In many real situations, both can appear, but com ele is the safest and most natural choice for a simple idea of having a conversation.

Examples:

• Vou falar com ele depois da reunião.
  = I’m going to talk with him after the meeting.
• Vou falar para ele que chegarei tarde.
  = I’m going to tell him that I’ll arrive late.

Because de + a contracts into da in Portuguese.

So:

• de + a = da

That means:

• depois da reunião = after the meeting

This kind of contraction is very common:

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

So depois da reunião is the normal form.

Portuguese often uses articles where English does not.

• depois da reunião = after the meeting

In this sentence, a reunião refers to a specific meeting, so the article sounds natural and expected.

Without the article, depois de reunião, it would sound incomplete or unnatural in most normal contexts.

It is a periphrastic future: a future expression made with two parts.

Structure:

• ir (conjugated) + infinitive

Here:

• vou = first person singular of ir (to go)
• falar = infinitive (to speak / to talk)

So:

• eu vou falar
• você vai falar
• ele/ela vai falar
• nós vamos falar
• eles/elas vão falar

This is one of the most important future patterns in Brazilian Portuguese.

Very often, yes, when something comes after it.

Examples:

• depois da reunião = after the meeting
• depois do almoço = after lunch
• depois de trabalhar = after working

So depois commonly appears as:

• depois de + noun
• depois de + infinitive

In your sentence:

• depois da reunião
  because de + a reunião = da reunião

Yes.

• depois da reunião = very common, neutral, everyday
• após a reunião = also correct, but often a bit more formal or written

So both mean the same thing here:

• Vou falar com ele depois da reunião.
• Vou falar com ele após a reunião.

In everyday Brazilian Portuguese, depois da reunião is usually the more natural choice.

Because Portuguese word order follows the verb’s normal pattern:

• falar com alguém

So the pieces stay together in this order:

• falar
  • com
    • ele

Portuguese prepositions go before the pronoun or noun:

• com ele
• com ela
• com o gerente
• com a professora

So:

• Vou falar com ele ✅
• Vou falar ele com ❌

Not in the same way here.

For this sentence, com ele is the normal form:

• Vou falar com ele.

Lhe is an indirect object pronoun, but falar com uses the preposition com, so com ele is the straightforward and natural choice.

In some contexts, lhe can appear with falar in more formal or different structures, but for learners, it is best to remember:

• falar com ele/ela/você = the normal pattern

In Brazilian Portuguese, reunião is pronounced approximately like:

• heh-oo-nee-OWN

A few key points:

• the r at the beginning is usually pronounced like an English h in many Brazilian accents
• the final -ão is nasal, which is very common in Portuguese
• the stress falls on the last syllable: reu-ni-ÃO

So the strongest part is:

• reuniÃO

Yes.

Portuguese falar com ele can correspond to both:

• talk to him
• talk with him

English sometimes distinguishes them slightly, but Portuguese often uses com naturally for both ideas in everyday speech.

So the sentence can imply:

• speaking to him
• having a conversation with him

The exact nuance depends on context.

It can move.

The version in your sentence is very natural:

• Eu vou falar com ele depois da reunião.

But you can also say:

• Depois da reunião, eu vou falar com ele.

Putting depois da reunião first gives it more emphasis, like:

• After the meeting, I’m going to talk to him.

Both are correct. The end position is especially common in neutral statements.

It is neutral and natural. It works well in both everyday speech and standard writing.

Why?

• Eu vou falar... is common spoken Brazilian Portuguese
• com ele is standard
• depois da reunião is standard and natural

So it is not slang, and it is not especially formal either. It is just normal, correct Portuguese.