Jespersen's cycle

Etymology
Described in 1917 by linguist Otto Jespersen, and named after him in Swedish linguist Östen Dahl's 1979 article Typology of Sentence Negation.

Proper noun

 * 1)  A process in historical linguistics by which negation is expressed first by a simple preverbal marker, then by a discontinuous marker (with elements both before and after the verb, as in the French ne...pas) and in some cases through subsequent loss of the original preverbal marker, and so on.