Archaic interjection expressing 'in that way' or 'so'. Not used in modern conversation; appears in classical texts.
古語では「しか」は「そのように」という意味の感動詞として使われた。
In classical Japanese, しか was used as an interjection meaning 'like that' or 'as such'.
Casual interjection of agreement or acknowledgment, similar to 'yeah' or 'uh-huh'. Used in informal speech.
「明日、映画に行かない？」「しか。」
"Wanna go to a movie tomorrow?" "Yeah."
友達の話に「しか」と相槌を打つ。
I nod along to my friend's story with an 'uh-huh'.
うん is the common modern casual 'yeah', while 然（しか）is a rarer, old-fashioned-sounding variant with the same agreement function.
however; but
moreover; furthermore; on top of that · nevertheless; and yet; even so
however; nevertheless
proper; appropriate; due; suitable
however; but; and yet
yes; yea; aye; affirmative · to be so
such and such; so-and-so
if so; in that case; then
even so; though that may be
Archaic kanji spelling; the word is now almost always written in kana.
Extremely rare historical kanji; not used in modern writing.
Standard modern kana spelling for both senses.
Derived from classical Japanese 然 (shika), meaning 'in that way'. The casual interjection sense developed from the archaic meaning, but the exact path is uncertain.
therefore; thus; so · well then; by the way
if not so; otherwise
appropriately; properly; as one should
now that; since it is the case that
to put into a state; to bring about a result
if not so; otherwise