É melhor que você não use a máquina agora, porque a secadora está ligada na mesma tomada.

Because é melhor que normally triggers the subjunctive in Portuguese.

So:

• você usa = indicative, plain statement
• que você use = present subjunctive, used after expressions of advice, doubt, desire, necessity, etc.

Here, É melhor que você não use... means something like It’s better that you not use..., so Portuguese uses the subjunctive.

The verb is usar, and the present subjunctive form for você is use.

Yes. That is very natural in Brazilian Portuguese.

You will hear both patterns:

• É melhor que você não use...
• É melhor você não usar...

The second one, with the infinitive usar, is often a little more conversational and common in everyday speech.

Very roughly:

• É melhor que você não use... = slightly more structured/formal
• É melhor você não usar... = very natural, often simpler in speech

Both are correct.

In this sentence, it is functioning as the subjunctive, because it comes after que in É melhor que você não use...

However, this is confusing for learners because the negative imperative for você has the same form:

• Não use a máquina! = Don’t use the machine!

So the form use can appear in both contexts:

• after que as the subjunctive
• in a command as the negative imperative

Here, because of the structure É melhor que..., it is best understood as subjunctive, not a direct command.

In everyday Brazilian Portuguese, a máquina often means the washing machine, especially in a household context.

So even though máquina literally means machine, in many homes people naturally use it to mean the washer.

That means this sentence likely contrasts:

• a máquina = the washing machine
• a secadora = the dryer

Portuguese often relies on context like this. If the context is clear, speakers may not feel the need to say máquina de lavar every time.

Here, está ligada means something like is connected / is on / is plugged in, depending on context.

The verb ligar has several related meanings, including:

• to turn on
• to connect
• to plug in
• to call someone on the phone

In appliance/electrical contexts, estar ligado/a often means the device is on or connected to power.

So a secadora está ligada na mesma tomada suggests the dryer is already connected to that same outlet, and using both may be a bad idea.

Also notice the agreement:

• a secadora is feminine
• so the participle/adjective is ligada, not ligado

Na is a contraction of:

• em + a = na

So:

• na tomada = in/on the outlet or more naturally into the outlet / to the outlet, depending on context

Tomada in Brazilian Portuguese means an electrical outlet, socket, or power point.

And mesma means same, agreeing with tomada, which is feminine singular:

• o mesmo for masculine singular nouns
• a mesma for feminine singular nouns

So:

• na mesma tomada = in the same outlet / into the same socket

Because here the word means because, introducing a reason.

Portuguese distinguishes these forms:

• porque = because
• por que = why / for what reason
• porquê = the reason
• por quê = why, usually at the end of a question

In this sentence, the second clause gives the reason for the advice, so porque is the correct form:

• ..., porque a secadora está ligada...

Portuguese uses definite articles much more often than English does.

So where English might say:

• don’t use the washing machine now, because the dryer is plugged into the same outlet

Portuguese naturally says:

• a máquina
• a secadora
• a tomada

This is normal and does not necessarily make the sentence extra specific. In Portuguese, the article often sounds more natural with everyday nouns.

Yes, agora can move around somewhat.

In the original sentence:

• É melhor que você não use a máquina agora...

that placement is very natural.

You could also hear:

• É melhor que você agora não use a máquina...
• Agora é melhor que você não use a máquina...

But these alternatives may shift emphasis a little:

• ...a máquina agora = neutral, natural
• Agora é melhor... = emphasizes right now
• você agora não use... = possible, but less common in everyday speech

So the original word order is probably the most natural choice for normal conversation.

Because they agree with feminine nouns.

In Portuguese, adjectives and adjective-like words usually agree in gender and number with the noun they describe.

Here:

• secadora is feminine singular, so ligada
• tomada is feminine singular, so mesma

Compare:

• o aparelho está ligado
• a secadora está ligada

and

• o mesmo cabo
• a mesma tomada

This agreement is a very important feature of Portuguese grammar.

Yes. Portuguese often drops subject pronouns when the meaning is clear, but with você, speakers frequently keep the pronoun because the verb form is shared with ele/ela.

So:

• É melhor que você não use... = very clear and natural
• É melhor que não use... = possible in context, but less clear by itself

Including você helps specify who is being addressed. That is one reason it sounds very natural here.