Learn Hardcore Portuguese (Portugal): Eu ainda não decidi em que candidato vou votar. - I still haven’t decided which candidate I’m going to vote for.

eu ainda não decidi
– This is slightly more neutral and very common.
– ainda (still / yet) + não (not) come together before the verb, forming a clear unit: ainda não decidi = I still haven’t decided yet.
eu não decidi ainda
– Also idiomatic.
– The adverb ainda after the verb puts a bit more focus on the fact that, up to now, the decision hasn’t happened.
– It can sound a touch more “spoken-language-like”, but it is far from wrong or unusual.

What you don’t say in Portuguese is eu não ainda decidi. The typical patterns are:

ainda não + verb
não + verb + ainda

Why do we say em que candidato and not just que candidato?

The preposition em comes from the verb votar em (to vote for [someone]) in Portuguese.

votar em alguém = to vote for someone
- votar em mim – vote for me
- votar em ti – vote for you
- votar em um candidato – vote for a candidate

When you turn that into an indirect question (in which candidate I’m going to vote?), the preposition has to stay attached to the question word:

em + que candidato → em que candidato
Literally: in which candidate (Portuguese em, English for here)

If you just said que candidato vou votar, you’d be “dropping” the preposition that the verb votar requires. That’s not grammatical in Portuguese. You either say:

em que candidato vou votar
em quem vou votar (if you don’t repeat candidato, see below)

Why is the preposition em used with votar instead of para or nothing at all?

In European Portuguese, the standard construction is:

votar em alguém / em algo = to vote for someone / something

So you say:

Vou votar em ti. – I’m going to vote for you.
Vou votar no João. (em + o João → no João) – I’m going to vote for João.
Não sei em quem vou votar. – I don’t know who I’m going to vote for.

Using para here (votar para alguém) is not standard for the meaning “vote for someone”. You might see votar para presidente (“vote for president” in the sense of the election is for president), but when the complement is the person you’re supporting, it’s votar em that you want.

Leaving out the preposition (e.g. votar um candidato) changes the meaning; that sounds like “to vote a candidate (into something)” and isn’t how you express whom you support in a normal election.

Could I say em quem vou votar instead of em que candidato vou votar? What is the difference?

Yes, you can absolutely say:

Eu ainda não decidi em quem vou votar.

This is very natural and common. The differences:

em que candidato vou votar
– Explicitly mentions candidato (candidate).
– Slightly more specific / explicit.
– Stylistically a bit more formal or careful.
em quem vou votar
– Uses quem (who), which always refers to people.
– More concise, very typical in everyday speech.
– The word candidato is understood from context.

Meaning-wise, both are practically the same: you’re talking about which person (which candidate) you’re going to vote for. The original sentence simply makes candidato explicit.

Why is it em que candidato vou votar and not vou votar em que candidato?

Both word orders are grammatically correct:

Eu ainda não decidi em que candidato vou votar.
Eu ainda não decidi vou votar em que candidato. ✅ (but unusual)

In practice:

In indirect questions introduced by verbs like decidir, saber, perguntar-se, etc., it’s much more natural to bring the question phrase to the front:
- … não decidi em que candidato vou votar.
- … não sei em que país vou morar.
The alternative … não decidi vou votar em que candidato is possible in theory, but it sounds awkward and is rarely used. Native speakers strongly prefer the first.

So the rule of thumb: in indirect questions, put the preposition + question word (em que candidato) right after decidi and before the verb of the inner clause.

Could I omit the subject eu and just say Ainda não decidi em que candidato vou votar?

Yes. In Portuguese, subject pronouns are often omitted because the verb ending already shows who the subject is:

Decidi clearly indicates eu (I) as the subject.

So these are both correct and natural:

Eu ainda não decidi em que candidato vou votar.
Ainda não decidi em que candidato vou votar.

Including eu can:

Add a bit of emphasis on I (I haven’t decided yet), or
Make it extra clear when context could be ambiguous.

But grammatically, eu is optional here.

Why does the sentence use vou votar instead of the simple future votarei?

Portuguese has two main ways to express future:

Periphrastic future:
- ir (to go) in the present + infinitive
- vou votar – I’m going to vote
Synthetic future:
- Future ending attached to the verb
- votarei – I will vote

In modern European Portuguese, especially in speech:

vou votar is much more common and sounds natural and neutral.
votarei is correct but tends to sound more formal, written, or “bookish”.

So:

Eu ainda não decidi em que candidato vou votar.
– Completely natural in everyday conversation.
Eu ainda não decidi em que candidato votarei.
– Grammatically fine, but may sound like written language, a speech, or very formal style.

That’s why vou votar is preferred in a typical sentence like this.

Could I just say em que candidato voto instead of em que candidato vou votar?

You could say:

Eu ainda não decidi em que candidato voto.

but it sounds odd in normal modern usage. Reasons:

The present tense in Portuguese can express future in some contexts (like English “I leave tomorrow”), but for one-time future actions that are not fixed schedules, the “ir + infinitive” future (vou votar) is more natural.
em que candidato voto feels more like a habitual action (in which candidate do I vote (whenever there’s an election)?), or a very stylized/literary structure.

So for a normal future event that hasn’t happened yet:

Prefer em que candidato vou votar in conversation and everyday writing.

What is the difference between ainda não decidi and ainda não me decidi?

Both exist, but they’re used slightly differently:

ainda não decidi
– Literally: I still haven’t decided.
– Focuses on making a decision about something (decidir algo).
– Very standard with an explicit object or clause:
- ainda não decidi em que candidato vou votar
- ainda não decidi o que vou fazer
ainda não me decidi
– Literally: I still haven’t made up my mind.
– Uses decidir-se (reflexive), focusing more on your internal state of having or not having made up your mind.
– Often used without immediately specifying the object:
- Ainda não me decidi. (I still haven’t made up my mind.)
  – If you add the object, you usually use a preposition:
- Ainda não me decidi quanto ao candidato.
- Ainda não me decidi sobre o que vou fazer.

In your exact sentence, ainda não decidi em que candidato vou votar is the most natural phrasing, because you immediately specify what you haven’t decided.

Why is the negative built as ainda não and not something like não ainda or ainda que não?

For this meaning (I still haven’t… / I haven’t yet…), the normal pattern is:

ainda não + verb
- Eu ainda não decidi. – I still haven’t decided.
- Ele ainda não chegou. – He hasn’t arrived yet.

não + verb + ainda
- Eu não decidi ainda.
- Ele não chegou ainda.

But:

não ainda decidi is not grammatical.
ainda que não decidi means something completely different.
- ainda que = even if / even though (concessive conjunction), not “still/yet”.

So to express “not yet”, think ainda não (before the verb) or não … ainda (after the verb), not não ainda in front of the verb and not ainda que.

Is this sentence specific to European Portuguese, or is it also used in Brazilian Portuguese?

The sentence:

Eu ainda não decidi em que candidato vou votar.

is perfectly natural in both European and Brazilian Portuguese. The grammar and word choice are standard across the language:

ainda não decidi – same in both varieties.
votar em (someone) – same preposition.
em que candidato vou votar – same structure.

The main differences between European and Brazilian Portuguese here would be pronunciation and intonation, not vocabulary or grammar.