及び【および】

及び is a formal conjunction meaning "and" or "as well as", used to connect nouns or noun phrases. It serves the same basic function as と but is significantly more formal and is predominantly found in written language, such as legal documents, official notices, academic papers, business correspondence, and formal announcements.

Usage notes

及び typically connects two items (or groups of items). When listing three or more items, 及び is usually placed before the final item, similar to how "and" works in English formal writing. The earlier items may be connected with commas (読点) or ならびに並びに for hierarchical groupings.

及び vs. 並びに

In legal and highly formal contexts, ならびに並びに is used for a higher-level grouping, while 及び connects items at the same level. In everyday formal writing, however, they are used interchangeably.

In this example, 及び groups 教員 and 職員 together at one level, while 並びに connects that group to 学生 at a higher level.

Compared to と and や

• と – neutral "and", used in both spoken and written language - や – "and (among other things)", implies a non-exhaustive list - 及び – formal "and", used almost exclusively in written/official contexts

Using 及び in casual conversation would sound very stiff and unnatural.