Great, Something Else to Learn to Conjugate
Well, 90% of the time you run across subjunctive I, it will be in the third person. Unless you're going to be working for a German media outlet, you won't need to learn to write it. But here's how it works. For ANY verb, take the infinitive, remove the -n, and then do it like this:
ich gehe, du gehest, er/sie/es gehe, wir gehen, ihr gehet, sie gehen, Sie gehen
So if you want to write, "She says she's going to school today," but you're not sure she's really going, it would look like this:
Sie sagt, sie gehe heute in die Schule.
If you want to write, "She says that you're eating here today," but you want to imply that she doubts whether the person you're talking to is coming, it would look like this:
Sie sagt, du essest heute hier.