mutual intelligibility

A criterion used in LINGUISTICS, referring to the ability of people to understand each other. If two VARIETIES of speech are mutually intelligible, they are strictly DIALECTS of the same LANGUAGE; if they are mutually unintelligible, they are different languages. The criterion seems simple, but there are many problem cases. Two varieties may be partially intelligible – for example, because they share some vocabulary. Also, political or cultural factors may intervene, causing two mutually intelligible varieties to be treated as different languages (e.g. Swedish and Danish) or two mutually unintelligible varieties to be treated as the same language (e.g. the so-called ‘dialects’ of Chinese).