Linguistic distance
Linguistic distance is how different one language or dialect is from another. Although there is no uniform approach to quantifying linguistic distance between languages, the concept is used in a variety of linguistic situations, such as learning additional languages, historical linguistics, language-based conflicts and the effects of language differences on trade.
Measures
The proposed measures used for linguisitic distance reflect varying understandings of the term itself. One approach is based on mutual intelligibility, i.e. the ability of speakers of one language to understand the other language. With this, the higher the linguistic distance, the lower is the level of mutual intelligibility.