(By Ljuba N. Veselinova): "The maps in this and the following chapter show the distribution of suppletion in verb paradigms according to tense-aspect, imperative and hortative moods, and verbal number. Suppletion is defined as the phenomenon whereby regular semantic relations are encoded by unpredictable formal patterns. Cases where the paradigmatically related forms share some phonological material are examples of weak suppletion, as in English buy vs. bought, while cases with no shared phonological material are instances of strong suppletion, as in English go vs. went (Dressler 1985). These types reflect two ends of a continuum rather than an either-or opposition. Mel’čuk (1994) also introduces the criterion of uniqueness, i.e. in order to be classified as suppletive, the alternation shown between two paradigmatically related forms should be unique, in that no other two forms in the language show exactly the same morphophonological alternation, as in Spanish digo ‘say.pres.1.sg’ vs. dije ‘say.pret.1.sg’. The maps concentrate on strong and unique cases."