Dictionary of English - spelling rules

Some people are unsure whether to keep the final silent e of words when adding suffixes like -ed, -ing, -er, or -ly.

Some people are unsure whether to change y at the end of a word to i, when adding -ed, -ing, or -er.

Full becomes -ful when added to the end of a word:

Note also:

But:

When adding mis- or dis- to the beginning of a word, there is only one s unless the word itself begins with s:

When adding in- or un- to the beginning of a word, there is only one n unless the word itself begins with n:

Most people know the rule i before e except after c. This rule works with many words, especially if the sound is ee:

Exceptions (examples):

If the sound is ay the spelling is always ei:

When -ly is added to a word ending in y, the y changes to an i:

In British English, many verbs can be spelt either -ize or -ise. -ize is the usual US spelling. Note capsize, prize (to value) which must be spelt -ize.

Words spelt -ise (note that these words can only be spelt -ise; there is no choice in the matter):

It is not always easy to remember whether a word ends with -able or -ible. Most words end -able, and whenever new words are coined, they are usually spelt -able. There is no simple rule (it depends on the Greek or Latin word from which the word comes), but the set of commonly used words that end -ible is a fairly small one:

Most other adjectives end in -able.