If you are a citizen of 7 English speaking countries and have higher education than Bachelors' Degree (as well as No Criminal Record on your background check!), then yes you can still teach in Korea.
You need to apply permission to engage in Activities beyond the limits of current status (A3)
Applying for permission, you need to prepare these documents listed below.
2. Application form
3. Both parties Signed Contract
4. Copy of Employer's business certificate (학원 사업자등록증)
5. Copy of Employer's school registration certificate (학원설립자 운영 등록증)
5. Time Table (시간표)
6. Apostilled Copy of Degree
7. Apostilled FBI result
8. E2 health check Result
9. Fee 120,000 KRW
You can apply for ARC card at the same time by adding these extra documents.
1. 1 passport sized photo
2. SOFA ID card
3. Copy of Housing Contract
Before visit immigration office, the reservation is a must. please check out this link for how to make a reservation for the immigration office in Korea