Translation guide
The English prefix 'semi-' means 'half', 'partially', or 'occurring twice in a period'. In Japanese, there is no single prefix that covers all uses. The best choice depends on the specific meaning.
Expressing that something is halfway, incomplete, or partial in nature.
Expressing that something happens twice within a specified time frame (e.g., semi-annual).
The katakana セミ (semi) means 'cicada' and is not used as the prefix 'semi-'. Using it will cause confusion.
セミの声がうるさい
The cicadas are noisy.
半自動ドア
semi-automatic door
Prefix meaning 'quasi-', 'semi-', or 'associate'. Used for status, rank, or official categories. More formal than 半.
Adverb meaning 'somewhat' or 'slightly'. Used to express a moderate degree, similar to 'semi-' in informal contexts.
やや甘い
semi-sweet
Noun/adverb meaning 'half', 'midway', or 'partially'. Can be used like 'semi-' in some contexts, but less common as a prefix.
半ば冗談で言う
say half-jokingly
Phrase meaning 'every half year'. Can be used for 'semi-annual' but emphasizes the interval rather than the frequency.
半年ごとの報告
semi-annual report