How to say "rightly" in Japanese

• 正しくただしく
  adverbCovers 'rightly' meaning correctly or properly — doing, saying, or judging something in the right way. The core idea is correctness, and it is a less common word than 当然.
• 程よくほどよく
  adverbIts core meaning is 'moderately', to a suitable degree or amount; despite the glosses 'rightly' and 'properly', it is seldom the word you want for 'rightly', which concerns correctness or what is deserved.
• 当然とうぜんCommon
  adverbTakes 'rightly' in the sense of 'deservedly' — what happens, or should happen, as a matter of course because it is deserved. It is the common word of the three and the natural choice here.
  ボルボ衝突しょうとつしたので、うちの車くるまの方ほうが当然とうぜんひどい目めにあった。↗

  In the collision with a Volvo, our car naturally got the worst of it.

Use 「正しく」 for 'rightly' meaning correctly or properly, 当然 for the deservedly sense — what is due as a matter of course — and treat 「程よく」 as essentially 'moderately', seldom the word you want for 'rightly'.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 正しくただしくright
• 程よくほどよくrightly
• 当然とうぜんnaturally