I've done a lot of thinking about English spelling. It's the central preoccupation of my life. Pronunciation of a given language always changes over time. Generally, the language's writing system also changes in an effort to keep up and stay accurate. English spelling hasn't kept up so well since the Great Vowel Shift and Samuel Johnson.
Anyway, because English spelling is changing gradually and because American and British standards often disagree, we'll need to clear up some issues if we want to spell properly in an international setting (like the Internet). Here are some rules for choosing between competing spellings in Modern English.
The combinations "ae" and "oe", generally occurring in words of Greek origin, are seldom present in American English. If these sequences were to be consistently shortened to "e", little harm would be done, but such shortening is unreliable in American English today, which allows forms like "aerobic" and "coelacanth". Also, a few words, such as "algae" and "cristae", would be rendered a bit confusing. Therefore, "ae" and "oe" must be preserved in words like "aeon" and "amoeba".
Where variation exists between words ending in "se" and "ze", as in "analyse" vs. "analyze", the "se" spelling is typically favored by the British and the "ze" spelling by Americans. However, due to the phonological clarity and etymological accuracy of the "ze" form, a few influential British publishers advocate its use. So do I.
In British English, variation between words ending in "ce" and "se" is supposed to indicate related noun-verb pairs such as "practice" and "practise". Because many verbs end in "ce" and many nouns end in "se", this rule is not a reliable indication of word class. Also, new verbs are easily coined from nouns (and vice versa) all the time without an accompanying spelling shift. Therefore, this distinction should be maintained only in pairs that differ in pronunciation such as "advice" and "advise". In all other cases, the spelling closer to Middle English is preferred.
Where variation exists between "or" and "our", British English often, but not always, prefers the latter. In many words such as "laboratory", both varieties of English prefer the Latin "or" to the Old French "our". Therefore, "or" is preferred over "our" for consistency.
In words that might end in "xion", an ending of "ction" is preferred. Though the "xion" spelling is older is such words as "complexion", it stands in contrast to words like "connection", whose
form is preferred in both varieties of English.
Where variation between "c" and "k" or "ck" exists, "k" should be made to precede "i", "e", "y", "ae", and "oe" for clarity in pronunciation. When a word ending in "c" takes a suffix beginning with one of these vowels, a "k" should intervene.
Where variation between the word endings "y", "ie", and/or "ey" is possible, "y" is preferred over the archaic "ie" and the unusual "ey".
When a suffix other than "s" is added to a word ending in a single consonant, the consonant should be doubled only if its syllable has stress (primary or secondary) in the root word and retains it in the derivative. This allows for consonant doubling in "compelled" but not in "biased" or "tranquility". Words such as "appear", whose final syllable ends in a single consonant but also contains a vowel digraph, are an exception to this rule, with "appearing" being preferred over "appearring".
The digraph "ph" is sometimes replaced by "f", especially in informal or American writing. This adds no phonetic clarity and may weaken connections to ancient counterparts. Therefore, "ph" is preserved in words like "sulphur".
The digraph "gh" is a relic bearing little relevant phonetic information today. Still, its removal from English orthography would create homographs and be viewed by the educated public as mere sloppiness. Therefore, "gh" should (for now at least) be preserved in words like "dough", "laugh", "night", "plough", and "through".
Many words like "axe" and "glycerine" contain silent "e"s preserved in British English but typically omitted from the American variety. Because the spellings including these "e"s are generally older, they are preferred. However, if a suffix other than "s" is added and the silent "e" isn't needed to soften a preceding "c" or "g", it should be omitted. If a silent "u" exists only to keep a "g" from being softened (as in "catalogue"), it should be preserved only as needed.
Words ending in "re" in British English are generally (except for a few exceptions such as "acre" and "ogre") modified to end in "er" for American English. This practice is unnecessary for pronunciation as demonstrated by the frequent occurrence of words ending in "le" in both varieties of English. Also, a spelling such as "centre" is more harmonious with derivatives such as "central". Therefore, "re" is possible word-final.
In words like "cooperate" or "reelect", no diaeresis or hyphen is needed to separate the suffix from the rest of the word. In general, diacritics should not be required in English words. This means that "resume" is a fine spelling for both the verb and the noun.
When two equally accepted spellings compete, the older is preferred unless it contrasts with a more general pattern. Where a difference in meaning can be communicated through a difference in spelling, both spellings are kept.