Sem wi-fi, eu não posso abrir o site do banco.

Sem means without. Starting the sentence with Sem wi-fi sets the condition first: Without wi-fi...

This is very natural in Portuguese. You could also put it later:

Eu não posso abrir o site do banco sem wi-fi.

Both are correct. Starting with Sem wi-fi gives a little more emphasis to the lack of connection.

In Portuguese, wi-fi is often used without an article when talking about it in a general sense, just like without water, without money, without internet.

So:

• Sem wi-fi = without wi-fi
• Sem internet = without internet

You might hear an article in other contexts, such as:

• O wi-fi está ruim. = The wi-fi is bad.

But after sem, leaving out the article is very common.

Yes, it could be omitted.

Portuguese often drops subject pronouns when the verb already makes the subject clear. So both are natural:

• Sem wi-fi, eu não posso abrir o site do banco.
• Sem wi-fi, não posso abrir o site do banco.

Including eu can add emphasis or clarity. A learner will often see both styles.

Here não posso means I can’t or I’m not able to.

The verb is poder = to be able to / can.

• posso = I can
• não posso = I can’t

Important: não posso can also sometimes mean I’m not allowed to, depending on context. But in this sentence, because of Sem wi-fi, it clearly means I’m unable to.

Yes, and it would sound very natural:

• Sem wi-fi, não consigo abrir o site do banco.

The difference is small:

• não posso = I can’t
• não consigo = I can’t manage to / I’m unable to

In this context, both work. Não consigo may sound a little more like a practical difficulty, while não posso is a broader can’t.

Yes. In Portuguese, abrir is commonly used for apps, pages, links, files, and websites.

So abrir o site can mean:

• open the website
• load the website
• access the website

This is very natural everyday Portuguese.

You could also hear:

• acessar o site = to access the website
• entrar no site = to go on the website / enter the website

But abrir o site is completely normal.

Because Portuguese usually contracts de + o into do.

So:

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

That means:

• o site do banco = the bank’s website / the website of the bank

This contraction is required in normal Portuguese.

Yes. Literally, it is the site of the bank, but in natural English that is usually the bank’s website.

Portuguese often uses de constructions where English prefers an apostrophe:

• o carro do meu pai = my father’s car
• o aplicativo do banco = the bank’s app
• o site do banco = the bank’s website

Yes. Site is a very common Brazilian Portuguese word for website.

Examples:

• o site da loja = the store’s website
• o site do governo = the government website

In Brazil, site is used much more often than a more literal word like sítio, which normally means a rural property or small farm, not a website.

In Brazilian Portuguese, site is usually pronounced approximately like SAI-tchee.

A rough guide:

• sai like English sigh
• final te often sounds like tchee in many Brazilian accents

So it does not sound exactly like English site, even though the word comes from English.

Yes, and it would also be natural:

• Sem internet, eu não posso abrir o site do banco.

But the meaning changes slightly:

• Sem wi-fi = without wi-fi specifically
• Sem internet = without internet access in general

For example, if someone has mobile data, then sem wi-fi does not necessarily mean they are offline. But sem internet usually means they have no internet connection at all.

Yes. Portuguese allows some flexibility here.

All of these are natural:

• Sem wi-fi, eu não posso abrir o site do banco.
• Eu não posso abrir o site do banco sem wi-fi.
• Não posso abrir o site do banco sem wi-fi.

The basic meaning stays the same. Starting with Sem wi-fi emphasizes the condition first.

No. Banco can also mean bench or seat, depending on context.

But in this sentence, because of o site do banco, it clearly means bank as a financial institution.

Context usually makes the meaning obvious.

You may see different spellings, such as:

• wi-fi
• wifi
• Wi-Fi

All are seen in real life. The hyphenated form is very common and easy for learners to recognize. In casual writing, many people also write wifi.