教科

1. Origins, structure, and basic meaning

• Structure: 教科 (きょうか) is a subject category in a school curriculum. 好きな教科だった gives a preference; 教科と授業時間 lists curriculum fields.
• Basic usage: Language arts is described as a favorite childhood subject, and subjects are organized with class hours by grade.

2. Common pitfalls and similar expressions

• Personally favored subject and curriculum category
  • The first example evaluates one subject personally; the second handles multiple subjects administratively. Keep the subject category distinct from an individual class session 授業.