How to say "only" in Japanese

• だけJLPT N5approx.Common
  particleCovers restrictive 'only' — limiting an amount, extent or degree to what is named — plus 'just', 'merely' and 'simply'. The broadest of these words, it is the natural first choice for plain 'only'.
  来きたのはメアリーだけだった。↗

  No one came except Mary.
• ばかりJLPT N4approx.Common
  particleCovers 'only' as 'nothing but' or 'no more than': the named thing is what there is, exclusively and often repeatedly. Pick it when 'only' means exclusivity rather than a simple limit on quantity.
  あなたの妹いもうとはいつも自分じぶんの夫おっとのことで文句もんくばかり言いっている。↗

  That sister of yours is always complaining of her husband.
• まだJLPT N5approx.Common
  adverbMeans 'still' and 'as yet'; it comes out as 'only' only when something is still at an early or small stage. For plain restrictive 'only' it is seldom the word you want.
  まだ肉眼にくがんじゃ無理むりだよ。双眼鏡そうがんきょうだと、ちょびっとだけ見みえるかも・・・。↗

  It's still impossible with the naked eye. With binoculars you might be able to glimpse it....
• のみCommon
  suffix, particleCovers 'only' and 'nothing but' — something limited to what is named and nothing more. It overlaps closely with だけ and ばかり; for plain restrictive 'only', だけ is the more general choice.
  ただ結果けっかを待まつのみだ。↗

  We can but wait for the results.
• 唯一ゆいいつJLPT N3approx.Common
  no-adjective, adverbCovers 'only' as 'sole' or 'unique': the one and only of its kind, with nothing else of the same sort. Use it to identify something as the single instance, the only one there is.
  初はじめの一いち歩ほが唯一ゆいいつの難関なんかん。↗

  The first step is the hardest.

Use 「だけ」 for plain restrictive 'only' or 'just', 「ばかり」 when the sense is 'nothing but', 「のみ」 as a close synonym of 「だけ」, 唯一 for 'the sole, one and only', and 「まだ」 only when 'still' shades into 'only'.

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

• だけonly
• ばかりonly
• まだstill
• のみonly
• 唯一ゆいいつonly
• 単にたんにsimply
• ほんのmere
• オンリーonly
• こそit is ... that ...
• たったonly
• 一にいつにsolely
• に限ってにかぎってparticularly
• こっきりonly
• 僅々きんきんonly
• たかがonly
• っきりonly
• くらいのものonly
• ばっかonly
• に過ぎないにすぎないno more than
• ただにmerely
• 最初で最後さいしょでさいごfirst and last (time, chance, etc.)
• ただ一つただひとつsole
• ただただabsolutely
• せめてものminimum
• 一つひとつonly
• わずかonly
• あくまでafter all
• 高々たかだかonly
• いっぺんexclusively
• あくまでもafter all
• ばかしonly
• わずかにonly
• なればこそunique to
• せめてもminimum
• さえ(if) only
• でさえas long as (it is, you are, etc.)
• までonly
• ただonly
• ひとりjust
• きりonly
• 一方いっぽうjust keeps