しか and だけ: only

Both mean 'only', but しか forces a negative verb and adds a note of 'not as much as I would like' that だけ does not have.

Also known asshika dakeしかだけonly in japaneseshika nai

N / number だけだけ — only, just

Only しか / limit

だけ after a noun or a quantity means “only, just”.

休みは　日曜日だけです。

やすみは　にちようびだけです。

My only day off is Sunday.

一人だけ　来ました。

ひとりだけ　きました。

Only one person came.

だけ limits neutrally — “this much and no more”: 日曜日だけ, 一人だけ. Minna II adds しか + negative, which stresses that it is not enough (lesson 27).

In the textbooksMinna I, lesson 11

N しか～ませんしか — only (with negative)

Only しか / limit

しか + a negative verb means “only / nothing but”, stressing how little there is.

わたしは　ひらがなしか　わかりません。

I only understand hiragana.

しか always takes a negative predicate but the meaning is positive-limiting: “only”. It replaces は/が/を (ひらがなしか), and comes after other particles (ここにしかありません).

Compare だけ (neutral “just”) with しか〜ない, which adds a nuance of “that's all, not enough / not more”.

In the textbooksMinna II, lesson 27