Spoonerisms are named after the reverend W.A. Spooner (1844 - 1930) who was Dean and Warden of New College in Oxford, England. He is reputed to have made these verbal slips frequently. English is a fertile soil for spoonerism, as author and lecturer Richard Lederer points out, because our language has more than three times as many words as any others – 616,500 and growing at 450 a year. Consequently, there is greater chance that any accidental transposition of letters or syllables will produce rhyming substitutes that still make sense.
Spoonerisms are phrases, sentences, or words in language with swapped sounds. Usually this happens by accident, particularly if you're speaking fast. Come and wook out of the lindow is an example.
Of course, there are many millions of possible Spoonerisms, but those which are of most interest (mainly for their amusement value) are the ones in which the Spoonerism makes sense as well as the original phrase. Go and shake a tower and a well-boiled icicle illustrate this well (go and take a shower, a well-oiled bicycle).
Since Spoonerisms are phonetic transpositions, it is not so much the letters which are swapped as the sounds themselves. Transposing initial consonants in the speed of light gives the leed of spight which is clearly meaningless when written, but phonetically it becomes the lead of spite.
Mind Explorer/ October, 2013 13