Translation guide
In Japanese, parentheses are primarily used in writing. The most common type is the corner bracket 「」, used for quotations and emphasis. Round parentheses （） are used for supplementary information, similar to English. Other brackets serve specialized roles.
To quote someone's words or to highlight a term, similar to English quotation marks or italics.
Corner brackets are the standard Japanese quotation marks. They enclose direct speech, thoughts, or emphasized terms. In vertical writing, they are rotated.
彼は「はい」と言った。
He said, "Yes."
「ありがとう」と彼女は言った。
"Thank you," she said.
Double corner brackets are used for titles of books, movies, or for quotes within quotes.
『吾輩は猫である』は夏目漱石の小説です。
"I Am a Cat" is a novel by Natsume Soseki.
To add extra information or clarification, similar to English parentheses.
Round parentheses are used for supplementary explanations, readings, or alternatives. They function much like English parentheses.
彼は東京（首都）に住んでいる。
He lives in Tokyo (the capital).
この本は面白い（特に後半が）です。
This book is interesting (especially the second half).
To show the pronunciation of kanji characters, often in small kana above or beside the text.
In horizontal text, furigana is often placed in parentheses after the kanji. In proper typesetting, it appears as small kana above the kanji (called ruby text).
難しい漢字には読み方を添えることがあります。
People sometimes add readings to difficult kanji.
To indicate that something is optional or can be replaced.
Used to show that B is an alternative or optional part of A. Common in dictionaries or instructions.
参加者（希望者）は申し込んでください。
Participants (those who wish) please apply.
To insert the writer's comment or clarification into a quoted text.
Used to add a note or explanation within a text, similar to [sic] or editorial brackets in English.
彼は「それでいい（注：問題ない）」と言った。
He said, "That's fine (note: no problem)."
Corner brackets 「」 are for quoting speech or emphasizing words, while round parentheses （） are for supplementary information or readings. Do not use round parentheses for direct quotes.
彼は「はい」と言った。
He said, "Yes."
彼は東京（首都）に住んでいる。
He lives in Tokyo (the capital).
In formal writing, furigana is usually placed above kanji as ruby text, not in parentheses. Parenthetical readings are common in casual or digital contexts but may look unprofessional in print.