指摘

1. Origins, structure, and basic meaning

• Structure: 指摘 (してき) is an action noun, used with する, for identifying and calling attention to a problem or error.
• Basic usage: 先生に指摘された is a passive construction in which an error is pointed out, while 問題点を指摘する actively makes the problem the object identified.

2. Common pitfalls and similar expressions

• Agent in the passive and object in the active
  • In 先生に指摘された, に marks the agent of the passive action. In 問題点を指摘する, を marks what is identified; exchanging them would reverse who points out what.