Trudy lives in Canada, next to Jim, and is a teacher. Someone lives in Canada next to Jim, but someone else is a teacher.
Someone lives somewhere but no one who lives in Canada is a teacher.
If and only if Trudy lives next to Jim does she teach him. Trudy only teaches people who are not Jim. Trudy teaches anyone who lives next to her, except for Jim. If someone lives in Canada, next to Trudy, but isn't Jim, then Trudy will teach that person. Trudy teaches only Jim, but lives next to someone else.