Is "general affairs division" a correct grammar? I have a question about the noun whose function is adjective. I know " a book store" is correct and " books store" is wrong because "book" is used as a adjective. In this case, I believe the noun should be singular in general. However, when we concern the noun which is always plural, such as "people", "states", "economics", or etc, we can keep it plural and function as adjective. "States committee" or "Economics class" is also correct. However, I am not sure whether "general affairs division" is correct or not when we name a office. I know "Ministry of Foreign Affairs" is correct because there are many affairs. But I believe the group concept of "affair" is closer to that of "book" than that of "people". Thus, I wish you would answer the difference between "general affair division" and "general affairs division".