Compound nouns are often written in which forms?

• A. Hyphenated (two words joined with a hyphen) or written as a single word
• B. Two separate words with a space between them
• C. All uppercase letters
• D. Separated by underscores

Answer: (A)

Compound nouns are formed when two or more words come together to function as a single noun. In everyday written English, these are usually shown in two common spellings: a single word (closed form) or with a hyphen (hyphenated form). The closed form signals that the words have fused into one item, as in toothpaste or bookshelf. The hyphenated form keeps the link between the parts clear while showing they operate as one idea, as in well-being or mother-in-law. You’ll also see some open forms—two words with a space—especially when the compound is newer or when the elements still feel like separate words, like post office or living room. However, for standard prose, the hyphenated or single-word spellings are the typical choices, while all uppercase or underscores aren’t used for ordinary writing.