The ultimate guide to prefixes

The Ultimate Guide to Using Prefixes

Lesson by Kerin. Updated Feb 7th 2022

Improve and widen your advanced English vocabulary by using prefixes in English! Learn all about prefixes & how to use them.

This lesson is inspired by my student, Lucia!

Read and Listen

I was doing a lesson yesterday with Lucia and she was telling me about her long weekend in Copenhagen. Here is what she said to me:  “I had been looking forward to this trip for so long. But honestly it was not good. I had in my head this idea of how it would be and it wasn’t. It was disappointing.” 

Lucia and I are focusing on her vocabulary at the moment. She wants to widen her knowledge of words and expressions.  And so, I asked her to look closely at what she had just said: “But honestly it was not good.”

“Yes, I know,” she said. “It was not good, is not very advanced English, is it?” 

This made me smile – obviously this is something I’ve told her in the past. 

Anyway, I told her that a word she could have used instead was: anticlimax.  

She could have said: “I had been looking forward to this trip for so long. But honestly it was such an anticlimax. So disappointing.” 

She asked, “Is that a prefix?” 

Yes.” I said. 

Mmm.” She was thinking. Then she said, “How do you use prefixes? I think I could make my English a lot better if I could use them.”

I couldn’t agree more with her. Therefore, I thought this lesson could benefit Lucia and all of you who want to improve your vocabulary.

Let’s get to it!

The Ultimate Guide to Prefixes

What is a prefix?

Prefixes are a really common part of the English language – and if you learn how to use them it’s a fab way to boost your range of vocabulary. In fact, you probably use words already that are prefixes, without even realising you’re using them! Like: unbelievable or ex-boyfriend!

A prefix is a part of a word that can be joined to the beginning of another word, called the “root” word, to give it a different meaning. Sometimes it is just a simple letter that acts as a prefix and sometimes it is a lengthier word.


Good to know!

  • Non-” is the most commonly used prefix and can precede almost any English word. 
  • The prefixes “in-,” “un-,” “non-,” and “anti-” generally pair up with certain Latin derivatives, and form words like “indescribable,” “nonchalant,” and “antihero.”
  • The prefix “a-,” which means “without,” generally appears with Greek derivatives, as in words like “asymmetrical.”

As with most parts of the English language, rules aren’t as simple as they seem to be at first. There are always exceptions to every rule! 

However, this guide will definitely come in handy:  refer to it when you’re wondering if you can create a prefix or if you are wondering whether you should or should not use a hyphen when you’re adding a prefix to a word.

How do you use prefixes?


No.1: Keep the root

The spelling of the base word never changes. Simply add the prefix to the beginning of the base word. E.g un + employed is unemployed


No.2: Double letters are correct!

Be aware that double letters can occur. If you add the prefix un to natural, both the prefix and the base word retain their original spelling. The result is unnatural. Other examples are: irrational, misspell, innovation

prefix double letters

No.3: Sometimes you need a hyphen

When do we need to use a hyphen?

1: when you add a prefix to a proper noun* or a numeral 

trans-America, un-American, Pre-1939, mid-1960s 

*a proper noun is a noun that names specific one-of-a-kind items, and they begin with capital letters, no matter where they occur within a sentence

prefix with hyphen

2: after the prefix self. For example: Self + harm = self-harm, self + respect = self-respect

3: when you add the prefix ex meaning former: e.g., ex + president = ex-president

(Do not use a hyphen if ex means out of or away from, as in expand.)

4: when the prefix ends with the same vowel of the root word

e.g., “pre-existed,” “co-occur,” “anti-immune”

prefixes with hyphen

5: after the prefix re to prevent misreading or confusion with another word.

E.g., re-cover vs. recover

As in “Re-cover the boat when you recover from the flu.

And re-lay vs. relay

As in “Please relay the message that they will re-lay the tiles.”

One general rule of thumb* to remember is that if a compound word with a prefix can easily be misread or misunderstood, you should include a hyphen to make the word clearer.

The MEANING of prefixes

The first common use of prefixes is to create opposites. 

E.g., unhappy, counterintuitive, misconception, irrational, uncertainty

So instead of saying:

> He is not rational at all.

You can say: > He is irrational 

The idea that fortune cookies originated from China is a common idea, but it is false

>  The idea that fortune cookies originated from China is a misconception.

You see how that takes your English up a level!

Common use number 2

Prefixes are also used to indicate the idea of ‘too much’ or ‘not enough’. 

And we can use over and under to do this. 

For example: 

Rose is an overachieverShe intends to apply only to the top colleges next year. Whereas, Nathan is an underachieverHis teachers often describe him as an underachiever, despite his natural talent.  

UndercutBig supermarkets can undercut all rivals, especially small family-owned shops.

OverkillIs HBO risking overkill with its five ‘Game of Thrones’ prequels?

Prefix challenge!

  1. Can you spot two prefixes in each sentence?
  • Camping in sub-zero temperatures, the team soon learnt to cooperate.
  • He is semi-retired now, but he outlasted many younger men and women in the business.
  • She interacted with Greek speakers from an early age and that’s why she’s bilingual.

2. Can you think of a prefix for these descriptions:

  • A hero who has amazing powers
  • Twice every month
  • Grow too big for some of your clothes
  • Below the usual or required standard

Share your answers in the comments below!

Kerin Goodall Founder English Digital Academy

ps. See how you can move towards proficiency with my advanced English courses.

5 thoughts on “The Ultimate Guide to Using Prefixes”

  1. Dear Kerin,
    I have one question for the rule of Hyphen. It’s the number 4 rule that said that we need little dash when the prefix ends with the same vowel of the root word. But I don’t understand Why don’t we put little dash in the words with prefix like Unnatural and Irrational. It’s also with double “n” and “r.” Beside, sorry for cannot be with you in the lesson’s practice. since I can’t effort to purchase the practice and some lessons.
    Your lesson are very useful and provide me to improve my English a lot. Thanks for your guiding, Teacher.
    May God bless you and fulfill all you needs.

    Yours sincerely,

    1. Dear Angela,
      Thank you for the question!
      So we need a hyphen when the prefix ends with the same vowel of the root word: vowels are: A, E, I, O U.

      Whereas, Unnatural and Irrational are using double consonants (N and R are not vowels).

      Hope that helps!

  2. Is there a way to know exactly which prefix should I use before a root word? What makes me know that prefix DIS can be used with approve, appear, etc?

    1. No, unfortunately it doesn’t work like that. I know it’s frustrating because different prefixes in English can have similar meanings, such as un-, in- and non- all of which mean “not” or “opposite of.” Also, the prefixes mis- and ir- mean “wrong,” “wrongly,” or “incorrectly.” So even if you learn the meaning of the prefixes, it doesn’t always help. The best way to approach it is to start by learning high frequency vocabulary first.

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