SOME OF THE FIRST SHALL BE LAST.
The power of the letter S is such that there are many words which can take S added to the beginning, the end, both or neither. Examples include: it (giving the 'quad' it, sit, its, sits), end, care, cull, train, camper and printer. .Other letters also yield a few such quads, for instance: are and angle with the letter D, ape with the letter R, in with the letter K, as with the letter H, a with the letter T, and lum with the letter P.
However, transposing two or more consecutive letters from end to end is another matter. There are some trivial examples to be found, in which the transposition only results in the appearance of the same word: mama, papa, tutu, pawpaw, pompom, murmur, couscous, hotshots. Then there are examples that need upper-case to allow proper nouns to be used: ED/WIN/ED, AL/AN/AL, IN/PUT/IN, AM/ASS/AM, MA/NOR/MA, LOT/HAR/LOT, LA/BEL/LA, PE/SKY/PE, OT/TO/OT, SA/TES/SA. To be pedantic, it could be argued that all single-letter transpositions can also be viewed as multi-letter ones, since f/ree/f could as well be written ree/f/ree, but this is of no real interest here.
Leaving aside these oddities, examples of multi-letter transpositions are listed below, starting with words of four letters and progressing through to a final word-pair of ten letters. The slash symbol indicates where the second block of letters starts.
Four letters --
Ly/re, dy/ed, me/sa, me/ga, ch/ar, se/ar, mo/de, em/it, ic/er, er/go, ts/ar, ge/ed, st/oa, me/de, it/ch, ro/ta, ol/id.
Five letters --
Gle/an, se/rin, pas/ta, son/ar, loy/al, ze/bra, ced/ar, mit/re, up/set, pe/sto, pes/to, es/top, ver/se, bow/el, lit/re, as/ide.
As the possible words get longer, they are more likely to be compounds that break down into their component parts, like layout and outlay, and then there can be the question whether one of the pairs should be hyphenated. For instance, inbuilt is one word, whereas built-in is hyphenated. This is a bit of a minefield, because usage can change and dictionaries do not always agree.
In/here, al/pine, er/rimg, lay/out, list/en, st/ripe, ves/sel, st/able, cent/re, en/sate, in/case.
Seven letters --
Gun/shot, look/out, king/pin, spect/r, pay/back, hot/pots, ing/rain.
Eight letters --
Hots/pots, pin/tails, formal/in, tally/men.
Nine letters --
Piece/work, house/boat, owner/ship, work/house.
Ten letters --
It is fitting that this example comes from the world of music. The word 'transposition' has a particular meaning here, namely the playing of a passage in a different key to the one written in the score. The ten-letter word-pair is--
Transposition based on dividing a word into three sections, rather than just two, will be the subject of a second contribution.