How to say "considerable" in Japanese

• 大したたいしたJLPT N3approx.Common
  pre-noun adjectivalCovers 'considerable' in the sense of great, important, or significant: an amount or degree you evaluate as impressive. Typical when praising someone's ability, effort, or an achievement.
  それはたいした問題もんだいではない。↗

  That is not much of a problem.
• 著しいいちじるしいJLPT N1approx.Common
  i-adjectiveCovers 'considerable' when the amount or degree is striking and conspicuous — a change, difference, or progress so large it is immediately noticeable. Typical in describing remarkable growth or improvement.
  科学かがくは著いちじるしく進歩しんぽした。↗

  Science has made remarkable progress.
• 多分たぶんJLPT N5approx.Common
  no-adjective, na-adjectiveMatches 'considerable' in the sense of 'a lot of; much; many', but this use is marginal: 多分 is really the adverb 'probably', and it is seldom the word you want for considerable amounts.

Choose 「大した」 for a degree you judge great, important, or impressive, 「著しい」 for a change or difference so large it is striking, and treat 多分 as marginal, since it is mainly the adverb 'probably'.

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

• 大したたいしたconsiderable
• 著しいいちじるしいstriking
• ひとかどconsiderable
• 半端じゃないはんぱじゃないconsiderable
• 少なからぬすくなからぬnot a little
• させる(any) particular
• 多分たぶんa lot of
• ちょっとしたconsiderable
• 相当そうとうconsiderable