master · teacher

1. Origins, structure, and basic meaning

• Structure: 師 is used for teachers and professional practitioners; its on-reading is し.
• Basic usage: 教師(きょうし) means a teacher, while 医師(いし) means a doctor or physician.

2. Common pitfalls and similar expressions

• The first character distinguishes the profession
  • 教師 is someone who teaches students, while 医師 is someone who provides medical care. Both contain 師, but the complete word formed with the first character distinguishes teaching from medicine.