Just fyi, the word 同志 can also mean male homosexual. It's never used as a title (you'll still hear announcements in trains saying tong2zhi4), but if you use it to describe someone, it can mean homosexual. At least on the mainland.

Btw: 教jiao1 is to "teach"
叫jiao4 is to call, make someone do something, yell, etc.