同じ

1. Origins, structure, and basic meaning

• Structure: 同じ is read as おなじ and is an expression of sameness used directly before a noun or predicatively with だ.
• Basic usage: It can modify a school shared by two people or state that two boxes match in color and size.

2. Common pitfalls and similar expressions

• Before a noun
  • Use 同じ学校 directly without inserting な before the noun.
• Predicative form
  • 色も大きさも同じだ ends with 同じだ, while も…も groups both compared features.