丹念

1. Origins, structure, and basic meaning

• Structure: 丹念 is read as たんねん and functions as a noun or adjectival noun for careful, painstaking attention to detail.
• Basic usage: It modifies an action in 丹念に磨く and a noun in 丹念な調査.

2. Common pitfalls and similar expressions

• Difference from 丁寧
  • 丁寧 broadly means polite or careful; 丹念 stresses painstaking, thorough work with no detail neglected.
• Inflection pattern
  • Use 丹念に before a verb and 丹念な before a noun; it does not inflect as an い-adjective.