Meus fones de ouvido estão na mochila, porque eu fiquei de gravar a apresentação na biblioteca.

My headphones are in the backpack, because I said I would record the presentation at the library.

Breakdown of Meus fones de ouvido estão na mochila, porque eu fiquei de gravar a apresentação na biblioteca.

• eu: I
• estar: to be
• porque: because
• na: in the

Questions & Answers about Meus fones de ouvido estão na mochila, porque eu fiquei de gravar a apresentação na biblioteca.

Why is it meus fones de ouvido and not just one word for headphones?

In Brazilian Portuguese, fones de ouvido is a very common way to say headphones or earphones.

• fones = phones/headphones pieces
• de ouvido = for the ear / of the ear

So the full expression literally means something like earphones.

A few notes:

• fone = one earphone / one earpiece
• fones = headphones, earphones, earbuds, depending on context
• In everyday speech, Brazilians often shorten it to just fones

So Meus fones de ouvido is completely natural.

Why is fones plural? In English, headphones is plural in form, but sometimes we think of it as one item.

In Portuguese, fones is also treated as a plural noun, so the grammar agrees with that:

• Meus = my, plural
• fones = plural noun
• estão = are, plural verb form

That is why the sentence says:

Meus fones de ouvido estão...

and not:

• Meu fone de ouvido está... unless you mean just one earphone
• Meus fones de ouvido está... which would be incorrect agreement

So even if the object is one set of headphones, Portuguese still normally uses plural agreement here.