Learn Hardcore Portuguese (Portugal): O Pedro limpa o teclado todas as noites para o manter livre de pó. - Pedro cleans the keyboard every night to keep it dust-free.

In European Portuguese it’s common in everyday speech to put a definite article before people’s names (especially among family and friends). So o Pedro simply means “Pedro” and adds a familiar, colloquial flavor. In more formal contexts you can drop the article and say just Pedro.

Why do we say o teclado instead of simply teclado like in English when we say “the keyboard” or just “keyboard”?

Portuguese usually requires a definite article before singular, countable nouns when talking about something specific. So o teclado literally “the keyboard.” Omitting the article sounds odd unless you’re listing words in a dictionary or speaking in headlines.

Why is it todas as noites and not todas noites or todas de noite?

Portuguese needs the article before the plural noun noites, and when you use todos/todas you repeat the article: todas as noites. It literally means “all the nights,” i.e. every night.

What does para + infinitive express here? Could we use para que + subjunctive instead?

Para + infinitive expresses purpose (“in order to”). So para o manter livre de pó = “in order to keep it dust-free.” You could use para que + subjunctive (e.g. para que ele se mantenha), but that’s longer and more formal.

Why is the pronoun o placed before manter? In Brazilian Portuguese I’ve seen para mantê-lo.

Clitic placement differs by variety and by verb form. After a preposition like para, you normally use proclisis (pronoun before the verb) in European Portuguese: para o manter. If you attach it to the infinitive, you use enclisis and a hyphen: para mantê-lo. Both are correct, but para o manter is very common in Portugal.

Why is the pronoun masculine o? How would it change if the object were feminine?

Clitic pronouns agree in gender and number with their direct object. Here o refers back to o teclado (masculine singular). If it were a mesa (feminine), you’d say para a manter or para mantê-la.

What exactly does livre de pó mean? Could we use sem pó instead?

Livre de means “free from.” Livre de pó = “free of dust.” You can also say sem pó, “without dust,” and it’s perfectly understandable. Livre de often sounds a bit more formal or descriptive.

What’s the difference between pó and poeira? Both translate as “dust,” right?

Yes, both mean “dust.” In Portugal pó is very common for the fine particles you clean off a surface. Poeira is also used, sometimes with a broader sense (“dust or small debris”). In everyday speech you’ll hear limpar o pó more often.

Could I rephrase the whole purpose clause in another way?

Yes. Some alternatives:

…todas as noites para mantê-lo sem pó. (attach the pronoun)
…todas as noites a fim de o manter livre de pó. (more formal)
…todas as noites para que ele fique livre de pó. (para que + subjunctive)