She is a doctor. She isn't a teacher.
She is a soccer player. She isn't a nurse.
She is a nurse. She isn't a doctor.
They are students. They aren't teachers.
They are cooks. They aren't firefighters.
They are police officers. They aren't pilots.
He is a teacher. He isn't a student.
He is a pilot. He isn't a police officer.
He is a bus driver. He isn't a pilot.
They are firefighters. They aren't bus drivers.