Spelling obsessives will be familiar with the nineteenth-century joke suggesting that ‘fish’ should really be spelt ‘ghoti’: the ‘gh’ is pronounced ‘f’, as in ‘cough’; the ‘o’ is pronounced ‘i’, as in ‘women’; the ‘ti’ is pronounced ‘sh’, as in ‘nation’. Entertaining as the joke is, it is essentially cobblers, as David Crystal explains in this masterly book. You’d never use ‘ti’ to sound like ‘sh’ at the end of a word; and ‘gh’ is never pronounced ‘f’ at the beginning of one.

For all its hidden pitfalls, English spelling has a logic (only a quarter of English words are spelt irregularly), even if that logic is a complicated one. The reasons for its complications are essentially chronological: new invaders to this country