How to say "highly" in Japanese

• なかなかJLPT N4approx.Common
  adverb, na-adjectiveCovers the mild, often approving 'highly' — 'quite, considerably' — for something that turns out better than expected; it is softer than English 'highly' often sounds, and with a negative it means 'not easily, not readily'.
  あいつは、なかなかいい奴やつだぜ！↗

  He is a good joker.
• 大いにおおいにJLPT N3approx.Common
  adverbThe 'highly' that means 'very much, greatly': it scales an action, feeling, or effect, as in appreciating something highly or benefiting greatly from it.
  私は彼かれを大おおいに尊敬そんけいしています。↗

  I have a great regard for him.
• 甚だはなはだJLPT N1approx.Common
  adverbAn emphatic 'exceedingly': it lends weight to a strong judgment and is often found in regret or disapproval — the 'highly' of 'highly regrettable' or 'highly questionable'.
  彼かれはやたらに故事こじ来歴らいれきに詳くわしいけれど、それが人生じんせいの役やくに立たっているのかはなはだ疑問ぎもんだね。↗

  He has a great storehouse of knowledge about historical details but I seriously doubt that's of any use in life.

Choose 「なかなか」 for the mild, approving 'quite/highly' of praise, 「大いに」 for 'very much, greatly' with actions and feelings, and 「甚だ」 for emphatic 'exceedingly', typically in regret or disapproval.

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

• なかなかvery
• 大いにおおいにvery
• 甚だはなはだvery
• 嘖々さくさくhighly (renowned, praised, reputed, etc.)
• ごくごくextremely