重い

1. Origins, structure, and basic meaning

• Structure: 重い(おもい) is an i-adjective describing substantial weight or burden.
• Basic usage: It is used for a box difficult to carry alone and also for the weight of a responsibility.

2. Common pitfalls and similar expressions

• Conjugation
  • The negative is 重くない and the past is 重かった, with the final い changing according to the form.
• From weight to burden
  • 重い責任 expresses the importance and substantial burden of a responsibility.
  • Using the opposite 軽い here changes the sense of burden or weight attached to the responsibility rather than physical weight.