Spoonerisms are words or phrases in which letters or syllables get swapped. This often happens accidentally in
slips of the tongue (or
tips of the slung as Spoonerisms are often affectionately called!)
Do you know any of these in Spanish?
I used to say "se me lengua la traba", which is not exactly a 'spoonerism' as in this case the whole words are swapped...
In English there are a lot and these are funny... (like "a lack of pies", "it's roaring with pain" etc., etc.)
