恩知らず

1. Origins, structure, and basic meaning

• Structure: 恩知らず(おんしらず) describes a person or attitude that fails to acknowledge kindness received.
• Basic usage: It appears in accusations of ingratitude or accounts of a person's reaction to being called ungrateful.

2. Common pitfalls and similar expressions

• Negation within the word
  • 知らず carries the negative sense of not knowing here, leading to the assessment that someone does not acknowledge or appreciate 恩.
• A strong judgment about a person
  • 恩知らずだ is a stronger accusation than merely observing that one has not heard an expression of thanks.
  • 恩知らずと呼ばれる means being called such a person; whether the speaker agrees with that assessment is a separate matter.