40 Spelling Rules – Prefixes

40 Spelling Rules - Prefixes



Hello, and welcome to the second mini-lesson on The 40 Rules of English, where we break down every beginner rule you need to know in English and ESL. Last time we covered a lot of grammar, so this lesson in comparison is going to be a bit lighter! That said, prefixes are still very important, and just because we’re only tackling two rules, that doesn’t mean you can forget about them!


Let’s start off with a definition. And what better way to define prefix than by its prefix? Yes, confusingly (and appropriately), prefix has a prefix. It’s the prefix pre-. Pre- means beginning or before, as in, “they arrived on the continent pre 1600.” Here, pre stands alone because it counts as its own word. The meaning of the sentence must be, then: they arrived on the continent sometime before 1600.


So we have pre- defined, what does fix mean? An even easier word, here fix means to attach to something. Taken together, what is a prefix? Working from our definitions, prefixes are things attached at the beginning. OK, that’s a bit vague. Let’s clear things up.


Prefixes change the meaning of a word by attaching a few letters to the beginning of a root word. There are a lot of prefixes in English, so many that putting a list here would confuse and upset even us. However, finding prefixes and the root words they attach to out in the real world will help you figure out other words in different situations. If you know the word “ordinary” and the prefix “extra”, then you’d probably be able to figure out that “extraordinary” means something fantastic and over the top. All this to say that prefixes help you become better English writers, spellers, and learners.

Now let’s jump into our eleventh rule!


  1. Prefixes ending in vowels are added directly to base words to create new words.

Very rarely, prefixes are attached to the beginning of words using hyphens. This occurs in most words that use the prefixes all-, cross-, self-, or ex- (all-encompassing, cross-examine, self-loathing, ex-husband). Additionally, it’s a good idea to use a hyphen when the end of the prefix is the same letter as the beginning of the root word. For example, “co-occur” ends and starts with an “o”, and looks much less confusing than “cooccur”.


Even more rarely, prefixes themselves may stand alone as their own words. Some examples of this include super-, hyper-, pre-, over-, and under-. Most often, however, prefixes go at the beginning of words to create a brand new word. Let’s look at a few examples!


The prefix “pseudo-” means fake, while we all know what “science” means. Putting the two together, we get “pseudoscience”, or a science that’s been disproven but still believed to be true by some. Now that we know what “pseudo-” means, what do you think the word “pseudoallergy” means? You got it! It is something that resembles an allergy, but actually is not one.


Here’s another example. The prefix “mid-” means middle. If we know what this prefix means, what does “midnight” mean? Of course, you’ve probably heard this word before. However, now we know that it literally means “the middle of the night”, or 12AM! What do you think the word “midair” means? Correct! It means some point in the air.  


  1. Sometimes negative prefixes are added to words to create new words and change their meaning to its opposite.  

So far we’ve only covered prefixes that aren’t negative (besides maybe ex-). As you can see above, negative prefixes function like regular prefixes, but they often change the meaning to the opposite of the root word. Fortunately, the list of negative prefixes is a bit shorter than the others, so we can give you the most common ones here: in-, im-, un-, il-, dis-, ir-, non-.


If something is “legal”, then it is OK to do in the eyes of the law. However, if it’s “illegal”, then you are breaking the law if you do it. If someone is “illiterate”, then they are unable to read. If it is “unlikely” I will travel the world, then I probably won’t be going anywhere anytime soon. Can you think of some other examples you may have heard? What’s important to remember is that if you see these negative prefixes, it’s possible you may be dealing with the opposite root word.




That’s all there is to it! To recap, prefixes always go at the beginning of words. Attaching a prefix will change the meaning of the word. If it’s a negative prefix, the meaning of the word will change to its opposite. In few cases, prefixes require a hyphen.


Want to sharpen those skills and prove to yourself you have what it takes to master the first steps of English spelling? We’re proud of you (and we’re here to help)! That means you’re ready for mini-lesson three: suffixes. If you aren’t quite ready, that’s OK! Use this lesson as a guide, and keep practicing every day. Practice builds the confidence you need to tackle even the most difficult of concepts. Check out our paths, decks, and other lessons today! See you next time.