You use estoy for temporary states, things that can change I am awake is Estoy despierto she is sad is Esta triste You are in love is Estas enamorado I am > estoy you are > estas (singular casual) esta (singular formal) (s)he is > esta we are > estamos you are & they are > estan Soy is something that defines you and is not likely to change I am tall is Soy alto You are a man is Eres hombre I am > soy you are > eres (singular casual) es (singular formal) (s)he is > es we are > somos you are & they are > son As a note you can use both with things like happiness. I don't know why but you can translate I am happy as Soy feliz or Estoy feliz and it's correct And I don't think we need the auxiliary verbs do and does in Spanish, just as verbs Do and make in Spanish translate to the verb hacer

FOR EXAMPLE: YO SOY I AM A WOMAN= YO SOY UNA MUJER I AM TALL= YO SOY ALTA I AM A DOCTOR= YO SOY DOCTORA EXAMPLE: YO ESTOY I AM TIRED= YO ESTOY CANSADA I AM AT HOME = YO ESTOY EN CASA I AM READING= YO ESTOY LEYENDO

You use "yo soy" when you are talking about what you are. you use "yo estoy" when you are talking about an action that you are doing in a time.

Hi, for more info....This page explain verbs "SER" & "ESTAR" ( SOY & ESTOY ) http://spanish.about.com/cs/verbs/a/servsestar.htm

At first.. auxiliar verbs are not used in spanish.. Verb TO BE and SOY / ESTOY are the same thing. For example: I'm a student Yo soy un estudiante I'm at home Yo estoy en mi casa If you want to know more... contact me..