How to AD- Prefixes to Words

Welcome back to our Free Blogs Corner, where we cover a new topic each week, helping you understand the English language. Last week, it was all about the suffixes. This week, we will cover prefixes, including how to spot them, understand them, and examples of them. 

Prefixes are letters or a combination of letters that are put in front of a word to change the meaning. Just remember that a prefix is at the start of a word and a suffix is at the end of a word. There are just as many prefixes as there are suffixes, so we can’t list them all out, but we will explain the most common ones for you. 


Understanding the Suffixes

Before we go into what is a suffix, we’d like to tell you what isn’t! Letter combinations such as bio- or auto- are not listed below for a reason. They are actually combining forms. Combining forms are very similar to both affixes, but there are some key differences. Combining forms, unlike affixes, are substantial enough to construct a word simply by attaching to an affix, as when the combining form cephal- unites with the suffix -ic to make cephalic. A combining form differs from an affix in that it is generated from a separate word. In the term paratrooper, for example, para- is a combining form since it represents the word parachute. However, in the phrases paranormal and paramedic, para- is a prefix. A combining form can also be distinguished historically from an affix by the fact that it is a descriptively a word or a combining form in another language, such as the French mal giving English the mal- in malfunction.

Suffixes are added to the front of words to change the meaning. Each suffix normally has a particular meaning, except in the case of A- which has many! We’ll leave this one until last on our list. Prefixes can change positive words into negative ones, they can imply the intensity of the word, and they can give you a sense of time. Yes, one, two, or three-letter combinations can do all that! 


Here are some rules to cover a lot of prefixes: 

  1. The base word is never altered. Unlike suffixes where we are changing Ys for Is and dropping letters, you don’t have to worry. The spelling of the word never changes. 
  2. When adding a prefix to a word that begins with a vowel, you will normally hyphenate the word. For example, when adding pre- to adolescent, you will write pre-adolescent. This helps with the pronunciation of the word because if you spelled it without a hyphen, speakers would pronounce the word with “read” in the middle (preed-o-less-ent) instead of pre-adoll-ess-ent. 
  3. .You can also hyphenate proper nouns, like pro-African, and describing words for people, like non-smoker. 
  4. Hyphens can be used to help mispronunciation or confusion with a similar word. Unfortunately, there are some words that will start with a suffix accidentally, but that is just how it is spelled. For example, “recover” starts with re- but it’s not using a suffix. This means getting better. If we add a hyphen, it will change to re-cover or to cover something again. “Re-cover the boat when you recover from the flu.” [meaning: Cover the boat again when you are better from the flu]

Now that we understand a little more about prefixes, let’s go through some of the main examples that we use in everyday English. 


Negative Prefixes

There are a few prefixes that all turn the base word into a negative format. They are easily confused because they are very similar, but there are slight differences.


thumbs up and down negative prefixes


The prefix un means not, reverse action, deprive of, or release from. This is the most common negative prefix used. There are a few examples below of different ways to use UN prefixes.

  • Unable (not able to do something)
  • Unfair (it is not fair. It’s not right)
  • Untrue (It’s not true. It’s false.) 
  • Untie (reverse action. The opposite of tie. To open your shoelaces or loosen your bowtie.) 
  • Unfed (deprive of. Not fed. Therefore, you are hungry.) 



The prefix mis simply means wrong. This negative form doesn’t mean not, so that’s a great differentiator from the others! Here are some examples: 

  • Mistake (You made a mistake. You made an error.) 
  • Misunderstand (You have the wrong understanding of something. Please note: Although under- is a prefix, here it is used as a combining form.) 
  • Misinform (You gave the wrong information.) 
  • Misguided (You were guided on the wrong path)



The prefix dis also means not and the opposite of. Here are some examples: 

  • Disconnect (To disconnect cables is to plug them out. To feel disconnected from people is to feel alone). 
  • Disapprove (To not approve something) 
  • Dishonest (the opposite of honest)


Im-/ In-

The prefix im- can also mean not and opposite of. You may also see in- as well. There is no real difference between the two. However, if you’re not sure, but say it fast enough, nobody can tell the difference! Here are some examples of both below: 

  • Impossible (It’s not possible) 
  • Inactive (It’s not active) 
  • Impractical (the opposite of practical) 
  • Insignificant (the opposite of significant)


Time and Size Changing Prefixes

There are some prefixes out there that will alter the time or size of a word. They can make words mean “in excess”, and they can make the word mean before or after the event. 


prehistoric meaning dinosaurs


The prefix pre- is used when you want to convey that the base word is before the event. This changes the time period. Here are some examples: 

  • Prehistoric (before written history. The dinosaur era and beyond). 
  • Pre-exams (normally, practice exams before the actual exam or test). 
  • Pre-empt (It can be to take action before something happens which is a verb.)
  • Precondition (a condition that is already present. For instance, if you are sick and are explaining your symptoms to your doctor, but one may be a precondition from birth, like a heart problem.)



This prefix is the opposite of pre-. Post- will change the word to mean after the event. This also changes the time period. Here are some examples: 

  • Postapocalyptic (This is a mouthful, but just means after the apocalypse or the end of the world or after a destructive event. You’ll hear this in Sci-Fi movies and tv series such as Walking Dead. 
  • Postpartum (This means after pregnancy or birth.) 
  • Postmodern (Literally means after modern times. Normally used for futuristic terms in art and fashion). 



Re– is along the same lines with time changing, but means again. Using re- will tell you that the action has already occurred before and is now happening again. It is used a lot! Here are some examples: 

  • Recalculate (to calculate or do the math again). 
  • Reuse, Recycle (to use something again, you may use a plastic bottle over and over to save the environment) 
  • Repaint (to paint again. If your house is painted, but it needs a sprucing up or you’d like to change colour, you’ll repaint the house). 



Although the word on its own can mean to be energetic and giddy, the prefix Hyper- means more than or beyond. This exaggerates the size of the base word. Some examples are: 

  • Hyperactive (very, very active.) 
  • Hyperventilate (to breath excessively usually brought on by a panic attack) 
  • Hypersensitive (to be very, very sensitive) 



Like Hyper, this prefix also makes the word excessive or exaggerated, or completely. However, in some cases, it can also literally mean outer or over, depending on the base word. In this instance, it’s normally an actual object, like an overcoat (the coat that goes over an outfit). Here are some examples of the “excessive” meaning: 

  • Overexaggerate (completely blown out of proportion. “Billions of people are starving in the world” is an over-exaggeration as there are only 7 billion people on the planet and not all are starving. 
  • Overconfident (being too confident. Being cocky.) 
  • Overjoyed (being excessively joyous. This can be used in times of complete bliss, like a wedding or baby being born.) 



This changes the word to exceed the original meaning of the base word. Out- is used a lot when comparing two actions. See our examples below: 

  • Outnumbered (To have more than the other. For example, the other team outnumbers us by 10 people.)
  • Outmaneuver (To have more skills or plans than another. For example, he outmaneuvered me in chess.) 


It’s All about the A- Prefix

You’ll see A- being used a lot and there are lots and lots of different meanings for it depending on the base word. Here are a few definitions and examples of each: 

Not/ Without: asymmetric means not symmetrical or not evenly shaped. 

To/Toward: aside means to the side. Step aside means to step to the side. 

Completely: Aghast means to be completely shocked. 

In a particular state: Aglow means that something is glowing. The lights were aglow. 

asymmetric bridge

Prefixes: Some Honourable mentions

Semi-/Hemi- means half. For example, a semicircle is half of a circle. Think of the shape of the half-moon. 

Inter- means between something. For example, “interchange” is changing between two things. For example, what made the meeting exciting was the interchange of ideas from different disciplines.

Ex- can mean both previous and out. Ex-wife or ex-husband means there was a divorce. Exclude means “out”. To expand means to grow outwards, like the universe.



We hope you’ve enjoyed our blog on prefixes. Remember this is the rule of thumb and there are lots of irregularities that you’ll see while learning English. English is a funny language! All you need is time and practice. 

Don’t forget to book your next lesson with our industry-led teachers! 


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