Notes taken on language change

For reference: http://www.grammarphobia.com/blog/2009/01/laughter-daughter.html
                     http://www.theguardian.com/commentisfree/2014/mar/11/pronunciation-errors-english-language

-  Why don't "laughter" and "daughter" rhyme? It once had many different pronunciations, a few of these included 'DAFF-ter' (the one that sounds like 'laughter' but hese did not survive. 'DAW-ter' is the remaining pronunciation.

-  Letters in a lot of words that are now silent, such as 'g' in 'night' and the 'k' in 'knife' and the 'd' in 'Wednesday' did in fact used to be pronounced, but although the spelling of these words is still fixed and remains the same, the pronunciation of them has changed. A lot of it is to do with etymology, for example words like 'doubt' keep the b even though it no longer sounds because of its Latin origins. 
Going back to the word 'night', it has actually undergone many many different spellings over the years before we ended up with night as it is today. Some examples include 'nact' and 'nigt' which comes from languages like German and Greek. The English language is a complete amalgamation of Germanic, Romantic and Latin influence anyway. 

-  David Crystal published in his book information about consonant change and vowel change. for example the English 'cw' was swapped for the French 'qu' in words such as 'queue' and 'queen'.

-  Language change occurred in the Middle ages too, when it was realised the the letter 'u' was being way overused. To save time I won't rephrase this piece of info, so here is a direct quote from website 1; "Still other English spellings came about in the Middle Ages when scribes found that the letters “m,” “n,” “u,” and “i” caused readers difficulty because of all those vertical downstrokes of the pen (“m” + “I” was hard to tell from “n” + “u”). So “o” was substituted for “u” in words like “come,” “some,” “monk,” son,” and “wolf.”

Apart from ease of reading, “o” was sometimes swapped for “u” because, as Dennis Freeborn writes in his book From Old English to Standard English, “u was an overused letter. It represented the sound v as well as u, and uu was used for w.”"