一緒

1. Origins, structure, and basic meaning

• Structure: 一緒, read いっしょ, combines one 一 with joined thread or connection 緒 to express togetherness.
• Basic usage: 友人と一緒に食べる means doing something together, while 形が一緒だ means being the same.

2. Common pitfalls and similar expressions

• Distinguishing meanings
  • Use combinations such as と一緒に for company and が一緒だ for two things being alike.