Translation guide
The English verb "classify" means to sort things into groups based on shared characteristics. In Japanese, the most common equivalent is 分類する (bunrui suru), but depending on context, other verbs like 区分する (kubun suru) or 種別する (shubetsu suru) may be more natural. This guide covers the main ways to express "classify" in Japanese, from general sorting to technical categorization.
To sort items, ideas, or organisms into groups based on shared traits. This is the most common meaning.
The standard, all-purpose verb for "classify." Used for everything from library books to biological taxonomy.
図書館の本はジャンル別に分類されている。
The library books are classified by genre.
生物を分類するのは難しい。
Classifying living things is difficult.
Emphasizes dividing or separating into distinct sections. Often used for administrative or legal categories.
土地を用途によって区分する。
Classify land according to its use.
Means to classify by type or kind. More formal and less common than 分類する.
書類を種別して保管する。
Classify and store the documents.
To designate information as secret, confidential, etc.
Specifically means to classify as confidential or secret. Used in government or corporate contexts.
その文書は機密指定されている。
That document is classified.
A more general phrase meaning to treat something as secret. Less formal than 機密指定する.
この情報は秘密扱いにしてください。
Please classify this information as confidential.
To arrange according to a system, like taxonomy or data classification.
While 分類された情報 (bunrui sareta jōhō) is grammatically correct, it means 'categorized information,' not 'classified information' in the sense of secret. Use 機密情報 (kimitsu jōhō) or 秘密情報 (himitsu jōhō) instead.
これは機密情報です。
This is classified information.
For simple sorting tasks like organizing files or emails, 分類する is perfectly natural. You can also use 整理する (seiri suru) for 'organize,' but 分類する emphasizes grouping by type.
書類は日付で分類されています。
The documents are classified by date.
この情報は機密扱いです。
This information is classified.