¿(v)os?

[ElDanés]

One of the first times I were having Spanish at school we were going through reflexive verbs like llamarse and levantarse, and the teacher asked if anyone knew how the reflexive pronouns looked like. I raised my hand and went through the forms, but he stopped me when I came to the second person plural form, where I had said, vos. He said it was incorrect, and that I should use os instead. I was kind of surprised as I had learned it as being vos, but after I had surfed the internet, I realized that it seems like both are equally used. So my question is simply whether one of them are more correct than the other, and if there is a difference between them grammatically, or maybe regionally?

[Tomisimo]

Vos and os are different. Os is the second person plural and vos is a second person singluar form. Vos can be thought of as an alternative to tú, and is used in some parts of Central America and Argentina.

[ElDanés]

The second person singular? As far as I know, the second person singular form is te.

me llamo
te llamas
se llama
nos llamamos
vos/os llamáis
se llaman

[Tomisimo]

me llamo
te llamas / vos llamás (or something like that)
se llama
nos llamamos
os llamáis
se llaman

I just did a bit of research on voseo (the vos form), and the reflexive pronoun is generally te, just like with tú.

So... Tú te llamas, Vos te llamás.

[ElDanés]

Well, I should simply use os and not vos?

[Rusty]

Correct, as far as a reflexive pronoun.

Vos, used only in certain countries, is a subject pronoun (replaces tú, and has a different verb conjugation than tú). It also appears where ti can be used.
Quiero darte a vos este libro.
Quiero ir con vos al mercado.
Esto es para vos.
¿Cómo (vos) te llamás?

[ElDanés]

Okay, thanks both of you! :)

Now I better start using os!

[Rusty]

Good idea, but only if you're in Spain. It isn't used elsewhere (excepto la poesía u otras obras literarias).

[ElDanés]

Oh? Now I'm confused. What's used elsewhere then?

(I tried re-reading the posts, but I couldn't find it mentioned - sorry, if I missed it anyway)

[Tomisimo]

The vosotros/vosotras forms (informal pluarl) are only used in Spain. In the Americas, they use Ustedes.

[breadb]

The vosotros/vosotras forms (informal pluarl) are only used in Spain. In the Americas, they use Ustedes.
No, they use vos in Chile and argentina.....

[Jessica]

The vosotros/vosotras forms (informal pluarl) are only used in Spain. In the Americas, they use Ustedes.

right. that's why we don't use it in Spanish class.

[Rusty]

No, they use vos in Chile and argentina.....
The subject pronouns vos (2nd person singular, used instead of tú) and vosotros (2nd person plural) are not the same. Vosotros is used in Spain. Elsewhere, ustedes is used as the plural form.

For a full list of the countries that use vos, visit here (http://en.wikipedia.org/wiki/Voseo).