Prefixes | The Basics

I did a disservice by not covering prefixes after I did a post on suffixes. I'll make up for that now.

 A special THANK YOU to my former student Eunah K for giving me the inspiration for this post.

Prefixes are difficult to understand and use, especially went the root word is the same, like uninformed and misinformed. There's no rule to follow on their use. You have to read to really get a clear idea about how they are used. We won't go into all of them; we'll stick to the basics for now. For more, you check here , or see the picture below, for a list of common prefixes. 

Let's start with...

 mis = wrongly/badly
un = not


To be uninformed means a person isn't informed, but a person who is misinformed has received information that isn't correct. There's also the verb to misinform which means to give the wrong information to another person.

Actually, other prefixes also  mean not: il, im, ir, and in, but these can't always be used with the same words. For example, irinformed. The prefix, ir is usually used with adjectives like irrelevant or irreversible. 

re = again

pre = before


 A review of a movie isn't the same as a preview of a movie. A review of the movie Thor: Ragnarok can be found here on bleedingcool.com. Below, we can see a preview (now known as a trailer) of the movie.

The word able can take the following prefixes.

Unable - Bob is unable to attend the meeting (can't attend the meeting)

Disable - I won't disable my anti-virus software (to make the software unable to block viruses)

Enable - These new shoes will enable you to run comfortable on the sidewalk (to make you able to run on the sidewalk).

Often different prefixes can make words seem similar such as mistrust versus distrust. Both mean either a lack of trust or to view someone/something without trust. The only difference is that people distrust someone or something based on the information available or experience they have had; mistrust is a feeling of being uncomfortable or lacking confidence in someone or something.


Often, but not always, the sound of the word can help you decide if it's correct or not.

For example:

x You can irregard most of what Bob says. He's usually joking or wrong. 

o You can disregard most of what Bob says. He's usually joking or wrong. 


Yes, it's all a bit confusing. This is why it's important to read a lot to get an idea of how to use prefixes and other parts of speech.  

To practice prefixes you can try these exercises from english-grammar.at.

Prefixes
Noun Prefixes
Adjective Prefixes