Tudo depende de a Júlia confirmar o horário hoje.

This is one of the most common questions.

Normally, de + a = da in Portuguese:

• da escola
• da Maria
• da cidade

But in sentences like this, de a Júlia confirmar..., many speakers and grammars prefer not to contract de + a when a Júlia is the subject of the infinitive confirmar.

So here:

• Tudo depende de a Júlia confirmar o horário hoje.
• literally: everything depends on Júlia confirming the time today

Keeping de a separate helps show that a Júlia belongs with confirmar as its subject.

If you say da Júlia, it can sound more like something belonging to Júlia rather than Júlia doing the action.

In everyday Brazilian Portuguese, you may still hear contractions in similar contexts, but de a Júlia confirmar is a very standard and clear way to write it.

In Brazilian Portuguese, it is very common to use a definite article before a person’s name:

• a Júlia
• o Pedro
• a Ana

This does not mean the Júlia in natural English. It is just a normal feature of Brazilian Portuguese.

So:

• a Júlia = Júlia

Some regions and some styles use articles more than others, but in Brazil this is extremely common in speech and also appears in writing.

Because after depender de, Portuguese often uses an infinitive clause to express what something depends on.

So:

• Tudo depende de a Júlia confirmar o horário hoje.

means that the thing everything depends on is Júlia confirming the time today.

Compare:

• Ela confirma o horário hoje. = She confirms / is confirming the time today.
• Tudo depende de a Júlia confirmar o horário hoje. = Everything depends on Júlia confirming the time today.

After depende de, Portuguese is not using a normal finite clause here; it is using an infinitive structure.

Yes, you can think of it that way.

Portuguese has a special feature called the personal infinitive, where the infinitive can show who the subject is. But in the third person singular, the personal infinitive looks exactly the same as the regular infinitive.

For confirmar, the forms are:

• eu confirmar
• você/ele/ela/Júlia confirmar
• nós confirmarmos
• vocês/eles/elas confirmarem

So in this sentence, confirmar could be understood as a personal infinitive with Júlia as its subject, but the form is identical to the basic infinitive.

That is why you do not see any change in the verb.

You may hear that kind of contraction in real life, especially in speech, but many teachers and grammar references prefer de a Júlia confirmar in this structure.

Why?

Because de a Júlia confirmar makes the grammar clearer:

• de = required by depende
• a Júlia = subject of confirmar

With da Júlia confirmar, the structure is less transparent and can sound less careful in formal language.

So for a learner, the safest choice is:

• Tudo depende de a Júlia confirmar o horário hoje.

Tudo means everything.

So:

• Tudo depende de... = Everything depends on...

It is a very common way to say that the entire situation depends on one condition.

You could also say:

• Isso tudo depende de... = All of this depends on...
• Tudo isso depende de... = All this depends on...

But Tudo depende de... is already perfectly natural if the context is clear.

Horário can mean different but related things depending on context:

• time in the sense of an appointed time
• schedule
• timetable
• scheduled hour

In this sentence, confirmar o horário most naturally means something like:

• confirm the time
• confirm the scheduled time

For example, if two people are arranging a meeting, appointment, or delivery, confirmar o horário is very natural.

If the idea were specifically what time is it now?, Portuguese would usually use hora instead.

In this sentence, hoje most naturally goes with confirmar:

• Tudo depende de a Júlia confirmar o horário hoje.
• Everything depends on Júlia confirming the time today.

So today refers to the action of confirming.

In real communication, word order and context usually make this clear. If needed, Portuguese can make it even clearer:

• Tudo depende de a Júlia confirmar o horário ainda hoje.
  = Everything depends on Júlia confirming the time later today / by today.

Yes. Portuguese allows some flexibility.

For example:

• Tudo depende de a Júlia confirmar hoje o horário.
• Hoje, tudo depende de a Júlia confirmar o horário.
• Tudo depende de a Júlia hoje confirmar o horário. — possible, but less natural in many contexts

The original sentence is very natural. If you move hoje, the emphasis can change slightly:

• confirmar o horário hoje = emphasis on confirming the time today
• Hoje, tudo depende de... = emphasis on today as the relevant moment

Yes, that is possible in principle, especially if you are avoiding the article before the name.

So you might see:

• Tudo depende de Júlia confirmar o horário hoje.

However, in Brazilian Portuguese, using the article with names is very common, so a Júlia sounds very natural.

The version with the article can sound more colloquial and more Brazilian in many contexts.

Yes. Portuguese has a few ways to express this idea.

For example:

• Tudo depende de a Júlia confirmar o horário hoje.
• Tudo vai depender de a Júlia confirmar o horário hoje.
  = Everything will depend on Júlia confirming the time today.
• Tudo depende da confirmação do horário pela Júlia hoje.
  This is more formal and less conversational.
• Tudo depende de ela confirmar o horário hoje.
  = Everything depends on her confirming the time today.

The original sentence is a very natural way to express the idea, especially in neutral or semi-formal Brazilian Portuguese.

Because the verb depender normally takes the preposition de:

• depender de alguma coisa
• depender de alguém
• depender de acontecer algo

So Portuguese naturally builds this sentence with de, not directly with que.

That is why:

• Tudo depende de a Júlia confirmar o horário hoje.

is the expected structure.

A clause with que is possible with some verbs and expressions in Portuguese, but depender strongly prefers de.

A useful breakdown is:

• Tudo = everything
• depende de = depends on
• a Júlia = Júlia
• confirmar = to confirm / confirming
• o horário = the time / scheduled time
• hoje = today

So the structure is:

• [Main clause]: Tudo depende de...
• [Infinitive clause]: a Júlia confirmar o horário hoje

In other words:

• Everything depends on [Júlia confirming the time today].

That is the key grammar idea in the sentence.