Should I use "bookstore" or "book store"?

Bookstore is the correct spelling. Book store is incorrectly used instead of the compound word bookstore. In British English, bookshop is more commonly used. The plural form is bookstores or bookshops.

The hyphenated versions book-store and book-shop are also incorrect.

Compound words are two or more words that are combined to make a new word with a new meaning. They can be open compounds, closed compounds, or hyphenated compounds. Open compounds are words that stay separated by a space, such as living room. Closed compounds are words that are combined without a space, such as sunflower. Hyphenated compounds are combined by a hyphen, like merry-go-round.

Bookstore is an example of a closed compound word. It is always written as one word, and it is an American word that dates back to the mid-1700s. Today, it can be used to mean a physical store or an online store that sells books.

Let’s take a look at some examples:

Correct: I love supporting independent bookstores.
Incorrect: I love supporting independent book stores.
Incorrect: I love supporting independent book-stores.

Correct: The bookshop is closed on Mondays.
Incorrect: The book shop is closed on Mondays.
Incorrect: The book-shop is closed on Mondays.