Failed grammatical changes have attracted far less attention than successful ones. They are, however, ubiquitous. Some show a slowly descending S-curve, others decay abruptly, and still others appear to vanish only to revive at a later chronological stage. Some seem to interact with other changes (failed or not) while others are rather isolated. Some have more systemic impact than others, and some might even boost subsequent changes.

In this talk, a number of failed morphosyntactic changes in the history of Spanish will be addressed in an attempt to shed some light on questions such as the following: Are the reasons for failure only sociolinguistic in nature? What kinds of dynamics may lie behind variations in prestige? How can failed changes interact among themselves and/or with triumphant changes? What could motivate ‘pendular’ changes? How does failure relate to textual variation? Is it possible to identify patterns of diffusion in failed changes? Is there any relationship between linguistic failure and linguistic creativity? And, finally, is morphosyntactic failure (or its concrete expression) predictable to some point?