• 3-minute read
  • 29th January 2018

Spelling Tips: Understanding Suffixes

In English, you can often build new words by attaching a suffix to the end of an existing word. We can add the suffix ‘-er’ to the word ‘proofread’, for example, to make ‘proofreader’ (i.e. a person who proofreads).

Nice and simple, eh? If only life were always that easy. Unfortunately, there are dozens of suffixes in English, which can be confusing if you’re not sure about using them. But what exactly are suffixes? And how are they used?

What Are Suffixes?

As suggested above, suffixes are common word endings. The ‘-er’ suffix used in the introduction to this post, for example, is often attached to a verb (e.g. ‘work’ or ‘employ’) to create a noun that stands for the person who performs the action (e.g. a ‘worker’ or an ‘employer’).

However, not every suffix can be added to every word. For instance, while we can add the suffix ‘-ful’ to the word ‘care’ to make ‘careful’ (i.e. something characterised by care), we can’t add it to the word ‘work’ to make ‘workful’. There is no strict reason for this: it just isn’t standard English.

We’d rather be beautiful than ‘workful’ anyway.
(Photo: Alex Brown/flickr)

Nor is every word that ends in a suffix based on a common English word. The suffix ‘-logy’, for instance, is familiar from words like ‘biology’ and ‘geology’. However, you will not find the words ‘bio’ or ‘geo’ used by themselves (these are prefixes that go at the start of other words).

As you can see, suffixes vary from word to word! If you’re ever unsure whether a suffix works with a particular word, then, make sure to look it up.

Spelling Changes

You also need to look out for sneaky spelling changes when adding suffixes to words. These can occur when adding a suffix to words that end in ‘y’ (which changes to ‘i’) or ‘e’ (which is sometimes dropped completely):

Beauty + -ful = Beautiful

Write + -ing = Writing

In Australian English, we also double the final consonant in some words when adding a vowel suffix. For instance, ‘run’ becomes ‘runner’ when we add ‘-er’. There are plenty of exceptions to these spelling rules, though, so make sure to double check any term you’re unsure about.

Some Common Suffixes

We won’t attempt to list every English suffix here, but we will provide a few examples below so that you know what to look for.

Some suffixes you might encounter include:





Capable of or susceptible to

Believe → Believable

Question → Questionable


Used to form nouns that refer to a particular domain or general condition

Free → Freedom

King → Kingdom


Used to form superlatives (i.e. the most of something or to the highest degree)

Big → Biggest

Happy → Happiest

-ise or -ize

Used for verbs, usually indicating a change

Computer → Computerise

Idol → Idolise



Hope → Hopeless

Care → Careless


Used for nouns that refer to a state or quality

Bright → Brightness

Dark → Darkness

Keep an eye out for other common word endings when you’re writing. With enough practice, you’ll soon spot the similarities in how different suffixes are used. And if you need more help, why not try our proofreading?

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