Double Consonant Words: What Are They and Spelling Rules to Follow

Double consonant words have two consonants next to each other. Some are always spelled with a double consonant (like the word “coffin”), while others only have a double consonant after adding a suffix. So, why doesn’t “turn” becomes “turnning?” 

In this article, you’ll discover when to double a consonant and when you shouldn’t.

What Are Double Consonant Words?

Simply put, double consonant words contain two consonants next to other, like “tunnel” or “occur.” However, some words will have a double consonant once you change their tense, like to a past tense or progressive tense. For instance, if you add the suffix -ing to “run,” it becomes “running,” with “nn” in the middle.   

The suffixes that can trigger a doubling of consonants are -ing, -er, -ed, and -est. However, 

The addition of vowel suffixes such as -ed -ing, -er, and -est often calls doubling consonants. However, there are rules to follow before doubling letters in a word.

When Do You Double Consonants?

You should double the consonants in a word if it meets the following criteria:  

1. One-Syllable Word with Consonant–Vowel–Consonant 

You should double the last letter if the word has the consonant-vowel-consonant pattern at the end. For instance, “grab” has “rab,” which follows the CVC pattern. 

This means you should double the letter “B” when you add -ed or -ing. So from the word “grab,” it becomes “graBBed” or “graBBing.”

With non-CVC words like “turn” (it follows a VCC ending), you will not double the last letter. 

Examples of CVC words:

  • Grab – Grabbed – Grabbing  
  • Run – Running
  • Big – Bigger

2. Multi-syllable Words with Vowel-Consonant (V-C) and A Stressed Last Syllable

You will also have to double the consonants if the word is multi-syllable with vowel-consonant (V-C) and a stressed last syllable. 

To better understand this rule, let’s look at the word “happen.” Most people double the letter N before adding the suffix. However, that’s wrong because the stress is in the first syllable, “ha-ppen.”

Now, let’s inspect the word “begin.” The stress is at the last syllable (“gin”). It also has a vowel-consonant pattern (“in”). Since it meets both rules, you should double the last consonant. So, from “begin,” it will become “beginning.”  


  • Begin – Beginning
  • Compel – Compelled
  • Occur – Occurring

3. Two-Syllable Word With a Short Vowel Sound Before the Middle Consonant

This rule does not involve adding a suffix and covers the basic spelling of a word. For instance, the word “butter” has “tt” in the middle because it is a two-syllable word with a short vowel sound. 

If we take another two-syllable word like “spider,” we don’t double the letter “D” in the middle because the word has a long vowel sound. 


  • Bitter
  • Dinner 
  • Coffin 
  • Rubber 
  • Muffin 

When Not To Double a Consonant?

As mentioned earlier, doubling consonants do not apply to certain words. Here are some rules when not to double a consonant: 

Vowel-Vowel-Consonant (VVC) Ending 

If the word’s last three letters follow the pattern vowel-vowel-consonant (VVC), you should not double the final consonant. 


  • Look – Looked
  • Rain – Raining
  • Clean – Cleaning

Words With Two Consonants at the End

If the word has two consonants, it also means that you shouldn’t double the consonant. For instance, the word “rent” has “nt.” Since it is two different consonants, you should just add the suffix without doubling letter “T.” 


  • Rent – Rented
  • Punish – Punished
  • Expand – Expanding

Consonant Blends

A consonant blend (-ng, -nk, -st) is two or more consonants where each consonant is sounded out. If you notice the word has a consonant blend at the end, it automatically means that you shouldn’t double the consonant. 


  • Link – Linked
  • Insist – Insisted
  • Blink – Blinked
  • Persist – Persisted 

Two-Syllable Word With a Long Vowel Sound in the First Syllable

You should never double the middle consonant in a two-syllable word with a long vowel sound in the beginning. 


  • Spider
  • Credit
  • Robin
  • Minor 

Words with X and W 

You should also not double the consonants of words with x and w because they typically form a consonant sound (like /ks/) or function as a vowel digraph. 


  • Fix – Fixed 
  • Glow – Glowed 
  • Tow – Towed 

American English vs. British English

There are many differences in accepted spelling between American and British English. For example, British words have extra vowels added to them (like tumour versus tumor). We also use “z” in American English, but in British English, the letter is swapped with “s.”  

Regarding consonant doubling, the rules are consistent but with a few glaring exceptions. The word “travel” meets the first syllable stressed CVC rule, so it should be “travelled,” but American English has dropped the extra letter “L.”

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