Linguistic and extra-linguistic predictors of mutual intelligibility between Germanic languages

We report on a large-scale investigation of the mutual intelligibility between five Germanic languages: Danish, Dutch, English, German and Swedish. We tested twenty language combinations using the same uniform methodology, making the results commensurable for the first time. We first tested both written and spoken language by means of cloze tests. Next we calculated linguistic distance at the levels of lexicon, orthography, phonology, morphology and syntax. We also quantified exposure and attitudes towards the test languages. Finally, we carried out a regression analysis to determine the relative importance of these linguistic and extra-linguistic predictors for the mutual intelligibility between Germanic languages. The extra-linguistic predictor exposure was the most significant factor in predicting intelligibility in the Germanic language area. The effect of attitude was very small. Lexical distance, orthographic and phonetic distances were the most important linguistic predictors of intelligibility.