時代

1. Origins, structure, and basic meaning

• Structure: 時代 (じだい) is a noun for an era or period characterized by shared conditions or features.
• Basic usage: It can refer to a historical era, a period in someone's life, or changing social times.
  • この道具は祖父が若かった時代に使われた。 — This tool was used when my grandfather was young.
  • 時代が変わっても残したい習慣がある。 — Some customs are worth preserving even as times change.

2. Common pitfalls and similar expressions

• Point in time and era
  • 時 can broadly indicate a time or moment, while 時代 more often refers to an extended period sharing historical or social features.