Final answer:
Effective teachers possess competencies in classroom management, subject expertise, and interpersonal skills, which together enable them to create a supportive learning environment, accurately teach subject matter, and communicate effectively with students.
Step-by-step explanation:
The three areas of competence that effective teachers possess are classroom management, subject expertise, and interpersonal skills. An effective teacher must be able to keep order and foster a conducive learning environment, demonstrating adept classroom management. The teacher also needs in-depth knowledge of the subject they are teaching; this subject expertise is vital for accurately conveying information and concepts to students. Lastly, interpersonal skills are necessary for communicating effectively with students, understanding their needs, and nurturing their development. This multifaceted competence enables teachers to deliver high-quality education and cater to varied learning styles and needs.