The Use of Hyphens with Prefixes

Identifying and understanding prefixes may not be as difficult as one may assume. Knowing when to put hyphens after prefixes is a completely different story. Fortunately, there are some general rules to be followed. You do not need to be professional paper writer to learn them. But first, let’s quickly recap what prefixes stand for.

A prefix is an affix used at the beginning of an existing word to create a new word with a brand new meaning. It can also change the grammatical function of a word in a sentence.

Example

✔️ My parents got married in the 1970s. vs My parents got married in the mid-1970s.

There is often confusion over whether a prefix should be used along with a hyphen. Should you write "anti-government" or "antigovernment"? Although you can’t rely on a single rule governing this, you can follow some guiding principles.

Guiding Principles for Hyphens with Prefixes

In most cases, you can decide whether to use a hyphen or not. If a word looks too unwieldy, you should use a hyphen. To be 100% sure, refer to a spellchecker.

Example

✔️ "Proactive" is not wrong, but it looks strange. If you feel the same way, write "pro-active."

If your prefix is located before a proper noun, you must use a hyphen. There is no other option.

Example

• ✔️ un-British
• ✔️ pro-Nazi

If a prefix ending and a word root have the same vowel, you should separate them with a hyphen.

Example

• ✔️ semi-informative
• ✔️ re-enter
• ✔️ ultra-aggressive

If a prefix ending and a word root have an "o," the situation becomes slightly different. If you are fine with how the word looks without a hyphen and your spellchecker indicates no mistake either, you can skip a hyphen.

Example

• ✔️ cooperate (co-operate is also possible)
• ✔️ coordinate (co-ordinate is also possible)
• ✔️ coowner (co-owner is also possible)

If one word with a prefix can be confused with another word without a prefix, the use of hyphen is inevitable. This issue mainly occurs with the prefix "re."

Example

• ✔️ re-cover vs recover
• ✔️ re-consider vs reconsider
• ✔️ re-press vs repress

Additional Guidelines

Now that you know how a hyphen functions in prefixed words, you can get some additional tips on its use. Let’s check them out!

	Hyphen	Hyphen
“in-,” “un-,” “non-,” and “anti-” stand before certain Latin derivatives		indescribable unfaithful nonchalant antibody
“a-” stand before some Greek derivatives		asymmetrical
"all-", "cross-", "ex-", and "self-" always need a hyphen	all-encompassing cross-cultural ex-boyfriend self-confidence
all prefixes preceding a proper noun, a number, or an abbreviation	trans-Atlantic network mid-1980s