Compound nouns
A compound noun is formed by joining together two words.
Sometimes these words remain separate.
Examples:
- washing machine
- coffee cup
- fairy tale
Sometimes they are hyphenated (joined together by a hyphen).
Examples:
- holiday-maker
- hold-up
- passer-by
Sometimes the words that make up a compound noun are joined together to make a new word.
Examples:
- teapot
- doorstep
- bedroom
There is no particular rule to determine which format should be used so the best advice is to check in a dictionary – although dictionaries will often disagree with each other!