A number of words that end in –our in British English, ends in –or in American English. Common examples are: colour / color; favour / favor; honour / honor

Most English dictionaries now include American and British spellings. In US dictionaries the difference is usually included in the headword with the variation given in parentheses.

For example: Favo(u)r

What this means is that this word is spelled favor in American English and favour in British English.

Here is a list of the most common spelling differences between American and British English.

American English / British English

Aluminum / aluminium

Analyze / analyse

Catalog / catalogue

Center / centre

Check / cheque

Colour / color

Defense / defence

Honor / honour

Labor / labour

Program / programme

Realize / realise

Theater / theatre

Notes

In British English, realize is also possible.

In American English, the consonant at the end of a word is sometimes not doubled. In British English, it is doubled when the consonant is an ‘I’.

Travel / traveling / traveler (US English)

Travel / travelling / traveller (British English)

Spelling: problem cases

Some words have two possible forms before –able and –age. The form without e is more common in most cases.

Examples are:

Like -> likable or likeable

Move -> movable or moveable

Love -> lovable or loveable

Two spellings are possible for the nouns dryer / drier and flyer / flier.

Words derived from dry can also be spelt with either y or i.

Dryly / drily

Dryness / driness

Judgement and acknowledgement can be spelt with or without the e after g.