Double Letters
One problem with English spelling is knowing whether to double the letter at the end of a word when a suffix such as -er is added.
fat 
fatter
Many short words consist of three sounds:
fit consists of:
- F (consonant)
- I (vowel)
- T (consonant)
These sounds constitute a syllable.
When we add a suffix to such words, we double the final consonant, unless the suffix itself begins with a consonant.
| one syllable word | vowel suffix | consonant suffix |
|---|---|---|
| beg | beggar | |
| stop | stopping | |
| plan | planned | |
| fit | fitted | fitness |
The situation is more complicated for words of two syllables. Say the words below aloud. What do you notice about them?
- preference
- preferred
- reference
- referred
In the first word in each pair, the strong stress is on the first syllable.
- preference
- reference
In the second word, the strong stress is on the second syllable.
- preferred
- referred
What then is the rule?
R: if the stress is on the first syllable when a suffix is added, the r is not doubled.
RR: if the stress is on the second syllable when a suffix is added, the r is doubled.
This rule applies to many words ending in r:
| refer | referred | referring | |
| occur | occurred | occurring | |
| BUT | offer | offering | offered |
The same rule applies to certain words ending in other consonants. There are also a few exceptions to this rule.
| stress on 1st syllable | stress on 2nd syllable | exceptions |
|---|---|---|
| benefited | omitted | developed |
| benefiting | omitting | enveloped |
| gossiped | equipped | worshipped |
| gossiping | equipping | kidnapped |
| focused | beginning | |
| focusing | beginner | |
| biased |
If the root word ends in l, the l is nearly always doubled, regardless of the stress, unless the suffix begins with a consonant.
- travel
- traveller
- travelling
- label
- labelling
- labelled
- jewel
- jeweller
- jewellery
- fulfil
- fulfilling
- fulfilled
- exception: fulfilment
- enrol
- enrolling
- enrolled
- exception: enrolment
Other exceptions include: appealing, paralleling
Note too: skill and skilful, where the second l in the root word is dropped because the suffix begins with a consonant. The suffix -ful has only one l: helpful, awful.
American spelling follows the above rules more closely than British spelling does, allowing, for example, traveling and kidnaped
Exercise
Instructions
Look at the words below. Add the suffix -ing to the root, doubling the consonant where necessary.
Remember:
stress on the first syllable: usually no doubling
stress on second syllable: usually doubling