Short monosyllables always double their final consonant.
Shop, shopping (NOT shoping)
Let, letting (NOT leting)
‘ie’ and ‘ei’
The general rule is to put ‘i’ before ‘e’ except after ‘c’.
Siege, believe, friends (Here ‘i’ comes before ‘e’.)
Receive, deceive, ceiling (Here ‘e’ comes before ‘i’ after ‘c’.)
There are, nevertheless, several exceptions to this rule.
Examples are: reign, neighbor, heir, seize, leisure, weird
‘se’ and ‘ce’
When a verb and a noun are spelt much alike, ‘se’ and ‘sy’ are verb endings and ‘ce’ and ‘cy’ are noun endings.
The following words are therefore verbs:
Advise, prophesy, practise, license
And the following words are nouns:
Advice, prophecy, practice, licence
Note that ‘promise’ is an exception to this rule as both the noun and the verb promise are spelt alike.
Words ending in ‘us’ and ‘ous’
Here the rule is simple. Nouns end in ‘us’. Adjectives end in ‘ous’. So we have the nouns phosphorus, census and genius and the adjectives jealous, unanimous and tremendous.
Words ending in final ‘e’
The common practice was to drop the final ‘e’ from words ending in ‘dge’ before the addition of ‘ment’. Example: judgment
But now it is not necessary to drop the final ‘e’ before ‘ment’ and you can write:
Judgement, acknowledgement, arrangement and advertisement
Note that the final ‘e’ is usually dropped before ‘able’.
Move, movable (Occasionally still moveable)
Like, likable (Occasionally still likeable)
Sale, salable (Occasionally still saleable)
Rate, ratable (NOT rateable)
Words ending in ‘ge’ and ‘ce’ are exceptions to this rule. Examples are:
Change, changeable (NOT changable)
Peace, peaceable (NOT peacable)
The final ‘e’ is dropped before ‘ous’, ‘age’ or ‘ish’. So we have:
Mile, milage (occasionally still mileage)
Note that courage is an exception to this rule.