I thought you were vs I thought you are

  • The "were" one means that you thought a person was a something in the past but may not be now. The "are" one means you think they are something now.
    Really, "I thought you are" doesn't make much sense. Even when you're talking about the present or future tense, when you are expressing a thought by saying "I thought...", you use the "were". You could say "I thought you were going to the store," even if you believe that the person will go to the store in the future. You would use "are" for something like "I think you are going to the store".