Mutually intelligible languages
A mutually intelligible language is one which can be easily understood by the speaker of another mother tongue. This usually occurs in genetically related languages which share similar features such as grammar, vocabulary and pronunciation which means the second language can be understood without the requisite study normally required in the acquisition of a language other than one’s own.
Some consider that mutually intelligible languages should not be classed as different languages but as variations of the same language. However, there are some varieties of what is basically the same language which are not mutually intelligible. This can occur because of the dialect continuum, which places dialects along a continuum with the furtherest from the centre being the least understood. The point comes where the dialect is so far from the others on the continuum that it becomes a stand-alone language, or a language in its own right.
The relationship between the mutually intelligible languages may be an uneven one, with the speakers of one language more able to understand the other than vice versa. This is true for Portuguese and Spanish speakers, with the former more comfortable with the language of the latter, and the same applying to Icelandic and Swedish speakers.
There are many languages with are mutually intelligible, some of which are Afrikaans, Dutch and Low German; English and Lowland Scots and Danish, Norwegian and Swedish. Of the Slavic languages, some which are mutually intelligible are Croatian, Bosnian and Serbian as well as Polish, Slavic, Czech and Sorbian.
Some languages are mutually intelligible only in their written or spoken forms, whilst others which could be expected to enjoy such a relationship because they are in effect related do not such as French which is a Romance language is not mutually intelligible with Italian, Spanish or Portuguese.