There are conjugation forms for each verb. When you want to know how to conjugate a verb, hover your mouse over it: click on the "conjugate " option, and you'll get a conjugation table.

Etre (present)= je SUIS nous SOMMES tu ES vous ETES (with a "hat" on the first "e") il/elle EST ils/elles SONT

(there's also the same "hat" on the first "e" of "etre")

I AM we ARE you ARE they/(formal you) ARE he/she IS they he/she ARE (plural that doesn't exist in the same way in English)

je - suis tu - es il/elle - est nous - sommes (plural) vous - êtes (plural) ils/elles - sont (plural)

The verb "Etre" (to be) is very important in the french language(so are "Avoir" and "Aller".) It would be good to learn the verb "Etre" off by heart. :-)

Tu es is less formal, whereas vous etes is more formal. Also, vous etes is used for a plural second person subject, as in "you all are"

Tu es = you are -singular informal

Vous êtes = you are -singular formal

Vous êtes = you are -plural.

Using tu es (informal) can be seen as being friendly or it may be taken as a lack of respect. Using vous êtes shows an awareness that a display of respect is warranted. Too much use of informal may result in you being seen as rude and thoughtless. Too much use of formal may make you seem distant and stiff.

Because in this case we are saying "You are". C'est is kinda like saying "It is a woman", but not really. So "est" is how the verb "to be" flexes "ce" (which is also how it flexes for il and elle).

Analogy, though not a really good one. "There is a woman". We're using "is" (verb to be) just like we do for he, she and it in that sentence. Imagine the same thing is happening with "C'est". Notice: I don't meant to say that there is = c'est. Also, ce is not the same as it.

So, anyway, "C'est" is like that because of "ce". "Tu es" is written as such because of "tu".

Je suis, Tu es, Il est, Elle est, Nous sommes, Vous êtes, Ils sont, Elles sont. That translates to I am, You Are, He is, She is, We Are, You are (plural), They are (masculine), They are (feminine).

"tu es" is the second person singular and is informal (for example, when you talk to a friend)

"vous êtes" is either the second person singular formal (for example, if you talk to someone you don't know), or the second person plural (for example, if you talk to a group of people).