eres,tu eres
If eres is you are then what is tu eres is it not the same thing?
1 Answer
Both "eres" and "tu eres" translate to "you are" in English. The tú is the pronoun (replaces a noun) and is generally not needed in Spanish the way it is in English.
I think about it this way; in English most of our verbs have very little variation in conjugation regardless of who is doing the action so we need the pronoun for clarity. E.g. I walk, you walk, he/she/it walks, we walk, they walk.
In contrast, the conjugation of spanish verbs leaves very little ambiguity as to who is doing the action, and therefore you dont really need the pronouns. E.g. Yo camino, tu caminas, él/ella camina, nosotros caminamos, vosotros caminaís, ellos/ellas caminan.
Because of this the pronoun is usually not used.
See http://www.spanishdict.com/topics/show/12 for more detail.