How to say "initially" in Japanese

• 初めのうちはじめのうち
  expressionCovers 'initially/at first' in the sense of an early period that is understood to be temporary or to change later. Reasonable but less common; often feels more like 'at first' than 'initially'.
  初はじめのうちは私は自分じぶんの誤あやまりが気きになりました。↗

  I was worried about my mistakes at first.
• 当初とうしょCommon
  noun, adverbThe common, go-to adverb for 'initially' in statements about plans, schedules, expectations, or how things originally were at the beginning of a project or undertaking.
  当初とうしょ抗議こうぎする人ひとはほんのわずかだったが、今いまやそこらじゅうから湧き起わきおこっている。↗

  At first only a few people protested, but now they're all coming out of the woodwork.

For 'initially' as a neutral adverb at the start of a plan, project, or situation, 当初 is the common, natural choice; 「初めのうち」 works for a temporary early stage that later changes.

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

• 初めのうちはじめのうちat first
• 当初とうしょat first