If there are no double spaces for a space between words (as noted above) it probably can still be done in a "best guess" style (meaning it has to be fixed manually afterwards)
- Take a say 100K Word list (most common words in English or whatever language, these lists are available on many locations)
- Sort that by length (longest word at the top)
- Do a find/replace starting with longest word "v e r y l o n g w o r d" -> "verylongword" so it processes: tissues, issues, issue, sues, sue, is for example.
- Now you should end up with a reasonably looking sentence with some words still incorrectly jumbled, but most likely not too bad.
Worth trying (its only a few lines of code, the sorting code in AHK was already posted, do that on a Word list and a simple parsing loop should do it.