when do you use etais (with an "s") and etait (with a "t")

[William Vigneaux]

 I have been studying French using Rosetta Stone and though I enjoy it very much, some things are very hard for me to understand.  The correct useage of the word etais/etait is one of these difficult things to understand, is there rule for when each is used?

[stu harris]

That's easy. étais is the first and second person, était is the third person.

J'étais

Tu étais

Il était

[William Vigneaux]

Thank you very much...this helps a lot.

[stu harris]

By the way, in the spoken language they sound exactly the same.