Carlos Cajina from Nicaragua asks:
Compound adjectives can be: 1. Joined by a hyphen 2. Appear as a single word 3. Appear as two separate words. Is there a rule - or set of rules - to know when to use any of the three alternatives described above?
Imran Munir from Pakistan asks:
Could you please underline the common pitfalls related to hyphen usage in English?
You'll find the hyphen used in compound nouns, in compound adjectives and in prefixes.
Most compound nouns are normally written as two separate words, although it is not a hard-and-fast rule:
hyphen usage, swimming pool, driving licence, human being, contact lens, news bulletin
The most common compound nouns which are normally linked with a hyphen include:
compound nouns function as adjectives, they are normally hyphenated.
Compare the following:
Most compound adjectives are made up of two, or sometimes three, words and are usually written with a hyphen between them. Here are some compound qualitative adjectives with nounsthat they typically collocate with:
Here are some compound classifying adjectives with nouns that they typically collocate with:
And here are a few compound colour adjectives with nouns that they typically collocate with:
Note that although compound adjectives are written with hyphens when they appear before nouns, they are usually written without hyphens when they are used as complements of the verb.
prefixes co-, non- and ex- are sometimes separated
from the following noun, adjective or verb by a hyphen: