English is famously difficult to spell, although its uniqueness in this respect has been considerably exaggerated. The often-quoted ghoti as a spelling of fish (gh as in tough, o as in women, and ti as in nation) would never be possible, as the values attached to those letters are dependent on their position in the word. It is true that there are some unnecessary complications, though, and there have been attempts over the years to simplify English orthography. Not many have succeeded.
If we take the linguist’s view that speech is primary and writing simply a secondary representation of speech, then spelling should not matter that much. But attitudes to spelling are extremely firmly rooted in the English-speaking world. Any attempt to make the system more logical, efficient, or practical has to get past the language mavens, those self-appointed guardians of correctness. But English has no official or regulated spelling – it’s a matter of convention. In such circumstances, it’s the dictionary’s job to guide users through the minefield and help them make the best spelling choices for the situation.
The most successful reform in the past 250 years has been Noah Webster’s in American English, with the adoption of spellings like flavor, theater, and anesthetic (compared to modern British flavour, theatre, and anaesthetic). The spelling bee, a type of spelling competition, took root in the US, and was a strong factor in popularizing and embedding Webster’s spellings.
Webster didn’t invent these spellings; they had been used by British writers too. But as they became more and more associated with the US, the assumption grew in Britain that they must be only American, and were therefore to be avoided. In this way the opportunity was lost to have a more efficient and more unified spelling for English.
In some ways the split is still growing. Organize is always spelled with –ize in American English, but in Britain both –ize and –ise are possible. Oxford University Press and several other publishers have always used –ize; the Times Literary Supplement uses it, as did the London Times until recently. But a growing (and mistaken) feeling that –ize is American has gradually ousted it from public life, to the extent that the Cambridge dictionary, though still showing organize as the main form, has now moved from saying UK also –ise to saying UK usually –ise, which is a more accurate representation of the picture in the early 21st century.
But in other ways we are moving closer together. Some British spellings with –ae– and –oe– (for example mediaeval and encyclopaedia) look distinctly old-fashioned now, and we can hardly believe that we once wrote oeconomy for economy. In fields like medicine and science, British scientists invariably use the simpler spellings (fetus, gynecology, sulfur). The artificial distinction in British English between program (in computing) and programme (in all other senses) is frequently flouted, and is likely to break down completely at some point. Spellings with –og (catalog) are seen increasingly in Britain where only –ogue used to be seen – although here American English is inconsistent too (dialog and dialogue are both used, and always synagogue).
Other languages reform their spelling by signing treaties and passing laws. Two recent transnational examples have been German and Portuguese: German now writes, for example, dass for daß (“that”), and Portuguese has ideia instead of idéia (“idea”). It seems unlikely that English will take any drastic steps to modernize its spelling, but some small progress can be noticed.