Learn Hardcore Portuguese (Portugal): Eu vou ligar para o Pedro depois do jantar.

This sounds natural and everyday in Portugal. Leaving the article out (Pedro, Maria) is also grammatically correct, but in European Portuguese it can sound a bit:

more formal, or
more “written”/careful, or
sometimes a bit distant.

So:

Eu vou ligar para o Pedro depois do jantar. – very natural in everyday European Portuguese.
Eu vou ligar para Pedro depois do jantar. – correct, but can sound more formal or less typical in casual speech in Portugal.

In Brazilian Portuguese, the article before names is generally less common or more regional, so this is one of the clear “Portugal vs Brazil” differences learners often notice.

Is the subject pronoun Eu necessary here, or can I just say Vou ligar para o Pedro depois do jantar?

You can absolutely drop Eu:

Vou ligar para o Pedro depois do jantar.

Portuguese is a “null subject” language: the verb ending often tells you who the subject is, so you don’t need to say the pronoun every time.

vou = I go / I am going
so the Eu is understood from vou.

Using Eu is fine; it can:

add emphasis: Eu vou ligar… (I will call, as opposed to someone else), or
simply reflect a more “learner-like” or careful style.

In natural speech in Portugal, you will often hear both versions, but dropping the pronoun is very frequent when the subject is clear.

What exactly does vou ligar mean? Is it more like “I am going to call” or “I will call”?

Vou ligar is literally “I go to call”, but functionally it is the normal way to talk about the future in conversation. In English terms it usually corresponds to:

“I’m going to call” (planned/intended action), or
very often simply “I’ll call”.

In everyday European Portuguese, ir + infinitive (vou ligar, vamos falar, etc.) is much more common than the simple future tense (ligarei, falaremos, etc.) when people talk about future actions.

So:

Eu vou ligar para o Pedro depois do jantar.
→ I’m going to call Pedro after dinner / I’ll call Pedro after dinner.

Could I say Eu ligarei para o Pedro depois do jantar instead of Eu vou ligar…? What’s the difference?

Yes, Eu ligarei para o Pedro depois do jantar is grammatically correct, but:

In spoken European Portuguese it can sound formal, bookish, or a bit stiff.
In writing (news, literature, formal texts) the simple future (ligarei) is more common.

In everyday conversation in Portugal, people overwhelmingly prefer:

Eu vou ligar para o Pedro depois do jantar.
or simply
Vou ligar para o Pedro depois do jantar.

So as a learner, use ir + infinitive (here: vou ligar) as your default future form when speaking.

What does ligar mean here? Does it literally mean “to connect” or “to call (on the phone)”?

Ligar is a very flexible verb in Portuguese. Some common meanings:

to turn on:
- Ligar a luz. – Turn on the light.
to connect / link:
- Ligar o computador à internet. – Connect the computer to the internet.
to call (on the phone):
- Ligar para o Pedro. – Call Pedro.

In your sentence, ligar clearly means “to call (on the phone)”:

Eu vou ligar para o Pedro depois do jantar.
→ I’m going to call Pedro after dinner.

The telephone meaning is extremely common; context tells you which meaning is intended.

Could I use telefonar instead of ligar? Is there any difference?

Yes, you can. In European Portuguese:

Ligar (para alguém) – very common and colloquial: to call (someone).
Telefonar (a alguém) – also correct; slightly more formal or neutral.

Examples:

Eu vou ligar para o Pedro depois do jantar.
Eu vou telefonar ao Pedro depois do jantar.

Both mean I’m going to call Pedro after dinner. In Portugal, ligar tends to be more frequent in casual speech, especially among younger speakers.

Why is it ligar para o Pedro and not ligar Pedro or ligar com o Pedro?

The normal pattern for “to call someone (on the phone)” is:

ligar para + person
- Ligar para o Pedro. – Call Pedro.
- Ligar para a Maria. – Call Maria.

or, especially in European Portuguese:

telefonar a + person
- Telefonar ao Pedro.

So:

ligar Pedro – not used with the telephone meaning; sounds wrong here.
ligar com o Pedro – would mean something like “connect with Pedro”, not “call him on the phone”.

Stick to:

ligar para alguém (all varieties)
telefonar a alguém (especially European Portuguese)

Could I say Eu vou ligar ao Pedro instead of para o Pedro?

Yes, in European Portuguese you will hear both:

Vou ligar para o Pedro.
Vou ligar ao Pedro.

Both are understood as I’m going to call Pedro.

Nuance:

para is very common and works everywhere in the Portuguese-speaking world.
a / ao with ligar is more typical in Portugal and can sound a bit more formal/traditional, but many speakers use it in everyday speech too.

As a learner focusing on Portugal, it’s useful to recognize both patterns. If you want one safe option, ligar para o Pedro is always fine.

What does depois do jantar literally mean, and why do instead of de o?

Literally:

depois – after
de – of
o jantar – the dinner

So depois de o jantar would literally be after of the dinner. In normal Portuguese, de + o contracts to do:

de + o = do
depois do jantar – after dinner.

This contraction is obligatory in standard Portuguese whenever de comes directly before the masculine singular article o:

de o carro → do carro
de o filme → do filme

So the natural form is:

Eu vou ligar para o Pedro depois do jantar.
not
… depois de o jantar. (grammatically understandable, but not how people actually say it).

Can I move depois do jantar to another place in the sentence, like at the beginning?

Yes, word order is flexible for time expressions. All of these are correct:

Eu vou ligar para o Pedro depois do jantar.
Depois do jantar, eu vou ligar para o Pedro.
Vou ligar para o Pedro depois do jantar.

The most neutral in speech is probably the original, but putting Depois do jantar at the beginning is also very natural, and sometimes emphasises the time a bit more.

Putting it in the very middle, breaking up vou ligar, is less natural:

✗ Eu vou, depois do jantar, ligar para o Pedro. – possible but sounds more written or marked.

How would I say “I’m calling Pedro after dinner” if I mean a scheduled future action, not right now?

In European Portuguese, if you mean a planned future call (not happening at this exact moment), vou ligar is perfect:

Eu vou ligar para o Pedro depois do jantar.
→ I’m going to call Pedro after dinner. (planned)

If you wanted to say I’m calling Pedro (right now), as in “I’m in the process of calling him”, you’d normally use:

Eu estou a ligar para o Pedro. – I’m calling Pedro (right now).

So:

vou ligar → future (soon, later, planned)
estou a ligar → present continuous, happening now

Both are very common in Portugal.

Where does the negation go? How would I say “I’m not going to call Pedro after dinner”?

The basic negation word is não, and it goes before the conjugated verb. Here the conjugated verb is vou:

Eu não vou ligar para o Pedro depois do jantar.
(With the subject dropped:) Não vou ligar para o Pedro depois do jantar.

Both mean: I’m not going to call Pedro after dinner.

How would I replace o Pedro with a pronoun, like “I’m going to call him after dinner”?

In European Portuguese, with ligar (para alguém), you typically use lhe for “to him/her”:

Eu vou ligar-lhe depois do jantar. – I’m going to call him/her after dinner.

Notes:

vou ligar-lhe – pronoun -lhe is attached to the infinitive ligar.
In affirmative sentences with periphrastic forms (like vou ligar), European Portuguese often places clitic pronouns after the infinitive or gerund (ligar-lhe, a ligar-lhe), rather than before vou.

So the pattern is:

Vou ligar para o Pedro. – I’m going to call Pedro.
Vou ligar-lhe. – I’m going to call him / her.