Summary

Language is a system that maps meanings to forms, but the mapping is not always one-to-one. Variation means that one meaning corresponds to multiple forms, for example faster ~ more fast. The choice is not uniquely determined by the rules of the language, but is made by the individual at the time of performance (speaking, writing). Such choices abound in human language. They are usually not just a matter of free will, but involve preferences that depend on the context, including the phonological context. Phonological variation is a situation where the choice among expressions is phonologically conditioned, sometimes statistically, sometimes categorically. In this overview, we take a look at three studies of variable vowel harmony in three languages (Finnish, Hungarian, and Tommo So) formulated in three frameworks (Partial Order Optimality Theory, Stochastic Optimality Theory, and Maximum Entropy Grammar). For example, both Finnish and Hungarian have Backness Harmony: vowels must be all [+back] or all [−back] within a single word, with the exception of neutral vowels that are compatible with either. Surprisingly, some stems allow both [+back] and [−back] suffixes in free variation, for example, analyysi-na ~ analyysi-nä ‘analysis-ess’ (Finnish) and arzén-nak ~ arzén-nek ‘arsenic-dat’ (Hungarian). Several questions arise. Is the variation random or in some way systematic? Where is the variation possible? Is it limited to specific lexical items? Is the choice predictable to some extent? Are the observed statistical patterns dictated by universal constraints or learned from the ambient data? The analyses illustrate the usefulness of recent advances in the technological infrastructure of linguistics, in particular the constantly improving computational tools.