1.
school
An educational institution. Can refer to any level: elementary school (小学校), middle school (中学校), high school (高校/高等学校), or the general concept of school as a place of learning.
学校 is the general term for any educational institution. It covers all levels from elementary to university.
SCHOOL LEVELS:
- 小学校: elementary school (6 years)
- 中学校: middle school (3 years)
- 高校 / 高等学校: high school (3 years)
- 大学: university
COMMON EXPRESSIONS:
- 学校に行く: to go to school
- 学校を休む: to be absent from school
- 学校が終わる: school ends (for the day)
- 学校生活: school life
Note that に marks the destination: 学校に行く. When 学校 is the topic or subject, は or が is used instead.