Se você clicar no link, o site vai abrir.

Se means if.

It introduces a condition: one thing happens if another thing happens.

In this sentence:

• Se você clicar no link = If you click the link / if you click on the link
• o site vai abrir = the site will open

So the whole sentence is a basic if X, then Y structure.

Great question. After se, when Portuguese talks about a real future possibility, it normally uses the future subjunctive.

So in Se você clicar no link, clicar is functioning as the future subjunctive, not just a plain infinitive.

The tricky part is that for many regular -ar verbs, the future subjunctive looks exactly like the infinitive:

• infinitive: clicar
• future subjunctive: clicar

So the form looks the same, but the grammar function is different.

You can see the difference more clearly with irregular verbs:

• Se você for... = If you go...
• Se você fizer... = If you do...

Those are clearly not infinitives.

Yes, it can often be omitted, but você is very common in Brazilian Portuguese.

Portuguese allows subject pronouns to be dropped when the meaning is clear. So you could say:

• Se clicar no link, o site vai abrir.

But including você makes the sentence clearer and more direct:

• Se você clicar no link, o site vai abrir.

In Brazil, speakers often use subject pronouns more than in some other varieties of Portuguese, so this sounds very natural.

No is a contraction of:

• em
  • o = no

So:

• no link = in/on the link, which in natural English becomes on the link

Portuguese very often contracts prepositions with articles:

• em + o = no
• em + a = na
• de + o = do
• a + o = ao

So em o link is not the normal form. Native speakers would say no link.

Because clicar in Brazilian Portuguese is usually used with a preposition, especially in everyday speech:

• clicar no link
• clicar na imagem
• clicar no botão

This works like click on in English.

You may sometimes see variation, but clicar no link is the most natural and common everyday phrasing in Brazil.

In Portuguese, nouns usually take an article much more often than in English.

So where English might say:

• the site
• or sometimes just site in certain contexts

Portuguese will very naturally say:

• o site

Also, site is treated as a masculine noun in Brazilian Portuguese, so the article is o.

This is very common with borrowed technology words:

• o site
• o link
• o mouse
  though usage can vary with some loanwords

Both are correct, but vai abrir is much more common in everyday Brazilian Portuguese.

• vai abrir = common spoken future
• abrirá = simple future, often more formal, written, or less conversational

So:

• O site vai abrir. = very natural in speech
• O site abrirá. = correct, but sounds more formal or stiff in many everyday contexts

Brazilian Portuguese often prefers ir + infinitive to talk about the future.

Because vai abrir is a two-part future structure:

• vai = a form of ir
• abrir = infinitive

This is the Portuguese equivalent of is going to open or will open, depending on context.

The pattern is:

• ir conjugated + infinitive

Examples:

• vou sair
• vamos ver
• ela vai chegar
• o site vai abrir

So abrir stays in the infinitive because vai is the part that is conjugated.

Because the sentence starts with the conditional clause:

• Se você clicar no link, ...

In Portuguese, when this if clause comes first, it is normally separated from the main clause by a comma in writing.

So this is standard:

• Se você clicar no link, o site vai abrir.

If you reverse the order, the comma is often omitted:

• O site vai abrir se você clicar no link.

Both word orders are correct.

Yes, absolutely.

That version is perfectly natural:

• O site vai abrir se você clicar no link.

The difference is mostly word order and emphasis:

• Se você clicar no link, o site vai abrir.
  This emphasizes the condition first.
• O site vai abrir se você clicar no link.
  This starts with the result.

Both mean the same thing.

Historically, it comes from the verb ir (to go), but in this structure it does not mean physical movement.

So vai abrir should be understood as a future marker:

• vai abrir = will open / is going to open

This is just like how English going to often does not mean actual movement:

• It’s going to rain does not mean the rain is physically going somewhere.

So don’t translate vai abrir word-for-word as go open. Treat it as a normal future expression.