N4
しか〜ない(数量)
しか〜ない(すうりょう)
No more than, Not exceeding, As few as・as little as, Only
今日は五キロしか走れない。
I can only run 5 km today.
Explanation
「しか」 after an amount must be followed by a negative at the end of the sentence, and means 'only'.
「1人しか来なかった」 (Only one person came).
The speaker feels it is too few, so there is a note of disappointment or regret.
Mixed up with
「だけ」 limits neutrally and can take a positive or a negative: 「1人だけ来た」 (Just one person came).
「しか」 must take a negative and carries 'that's too few': 「1人しか来なかった」.
「しか」 replaces 「が」 and 「を」; do not say 「×100円をしかない」.