how to say you are in spanish
You need to study lesson 1.11 which gives you both terms of "you are", ie, ser and estar.
Lesson 1.1 will teach you this and other greetings and give you some practice. Go to Learn Spanish and try it out.
how do you say " you are" in spanish
Your question seems to imply the (mistaken) idea that there should be one, and only one, way to translate these two words into some other language. In addition the the references already provided for "ser" and "estar", there are countless phrases which, in English, involve, "you are" but for which there is no direct correspondence in other languages. e.g. "You are hungry/cold." = "Tienes hambre/frío."
Worse yet, in English, "you are" can be used as a helping verb followed by the present participle of almost any verb to form a progressive tense (e.g. "you are running/eating/reading/etc.") Usually this would be the the appropriate form of "estar" in Spanish plus the gerundio.
Returning to my original point, it is a serious mistake to assume that a word (or pair of words) will always be translated the same way in some other language. If you stick to single, concrete nouns the chances of a single translation are not bad but when you have phrases, the likelihood of a "simple" translation fall off sharply. What seems, "obvious"/"natural" to you may seem very strange to a speaker of some other language.