Isn’t the English spelling system a wonderful thing? It’s so regular and predictable: who could look at words like knight, house, flour, debt or colonel and not know instantly how they are pronounced?
My apologies for the sarcasm, but the English language really is a deeply confusing and frustrating thing. There are languages where spelling and pronunciation are more closely related, where a ‘p’ is always pronounced ‘p’, rather than sometimes joining forces with ‘h’ to fulfil a role that would usually be part of the job description for ‘f’ (pharmacy, phantom, and so on) or making an entirely silent guest appearance (psychology and related words).
Amongst the many reasons for English spelling’s refusal to be sensible*:
Pronunciations changed but spellings stayed the same
English spelling was mostly standardised during the 16th and 17th centuries; unfortunately this was also the period during which pronunciation was going through one of its periodic shifts. This resulted in spellings that now look totally random – knight, for example, was originally pronounced more or less as it is spelt (roughly ku-nicht, with the ‘ch’ being similar to the last syllable of the modern Scottish ‘loch’). Gradually the pronunciation shifted while the spelling stubbornly stayed as it was, which is why there is now very little correspondence between the word’s pronunciation and its spelling.
A related phenomenon was the Great Vowel Shift where, for unknown reasons, from the 13th century people gradually started to change the way they pronounced various vowel sounds. As with knight, spellings often stayed the same while pronunciations changed, explaining spellings like house and mouse (originally pronounced hoos and moos**), as well as now non-rhyming poetry like
“I am monarch of all I survey….
From the centre all round to the sea”
which, at the time of writing (the late 18th century) would have rhymed***.
Spellings changed but pronunciations stayed the same
To confuse things even further, in some cases pronunciations have stayed put while spellings have changed. Flour – in the sense of finely ground grains – was usually spelled flower, until the ‘…our’ spelling gained popularity as a way of differentiating ground grains from blossoms. (The spelling was probably influenced by the French fleur, which now means just flower but once also meant flour, English not being totally alone in taking a seeming pleasure in causing confusion!)
The word debt, meanwhile, was, for much of its history, spelled dette, as it was (and is) pronounced. At some point, though, learned people decided that, as the word derived from the Latin debere – “to owe” – the English word should have a ‘b’ in it as well, even though no-one pronounced it that way. (See my earlier point re: sheer bloody-mindedness.)
Words follow the rules of another language
A further problem with English is that it sometimes seems as if it is not so much a language as a compulsive adopter of peripatetic words. Some adoptees are moulded into a form that fits more easily with ‘normal’ English orthography (in so far as such a thing exists), but often they keep their original spelling and / or pronunciation, regardless of whether or not this fits with standard English patterns. (See rendezvous, from French; psychology, from Greek; polka, from Czech; cipher, from Arabic, amongst many, many others.)
Perhaps not surprisingly, all this indiscriminate borrowing sometimes ends in confusion: colonel was adopted from both the French coronelle and the Italian colonnella, and somehow ended up with the Italian spelling and the French pronunciation. (Coronel was once an acceptable alternative spelling of the word, but it fell out of favour after a while.)
About the only thing that can be concluded from all of this is that the English language really should come with an appropriate warning sign, like the one at the top of this post!