It depends on two things: 1) who statement is addressed to and the number and 2) the noun gender of the object.
In Spanish, there are different ways of saying 'you':
The possessive adjective ('your', in this case) thus depends on the addressee as detailed in the above categories. Each has a corresponding possessive:
The ending of the Spanish word 'your' depends on the number and gender of the following noun, so the possessive for 'your brother' is different to that for 'your brothers'. For all 3 of the above categories just add an 's':
You might be familiar with the phrase 'mi casa es su casa' (literally, 'my house is your house', which can be better translated as 'make yourself at home'). We can see that the possessive here is 'su', as the host is addressing the guest in the polite register (though when I say this to a Spaniard I still replace 'su' with 'tu' if I know them even only vaguely well).
One final thing, in Spanish every noun has a 'gender', either masculine or feminine. This is can seem arbitrary to native speakers of English but you can easily find out the gender of a noun by looking it up in a dictionary. For the 'vosotros' form you need to agree the possessive with the gender of the object, as well as the number ('tu', 'tus', 'su' and 'sus' stay the same for both genders), by using an 'o' at the end for a masculine noun and an 'a' for a feminine one, so:
vuestro hermano, vuestros hermanos, vuestra hermana (your sister, speaking to a group of people), vuestras hermanas (your sisters).
This may all sound complicated, but once you know the 2 rules I stated at the very start of this answer you have the correct word for 'your' to go with any noun. There are practically no irregularities, with this, compared to French, for which you have to learn quite a number of exceptions for the possessives. Here are examples for each:
Hope this helps.
Tom Stubbs
[Tu] no eres español. In the spanish language, you dont tend to say the ' tu'
you: tu
tu no
To say "you too" in Spanish, you say "tu tambien".
you say = tu dices
tu has sido or tu has estado
tu y solamente tu
diga tu is you say in spanish
depends you could say: eres tu or es tu
¿Y tu? ("and you?")
y tu?
"Y tu?"