Polysynthetic language

Polysynthetic languages are highly inflected languages, i.e. languages in which words are composed of several morphemes.

There are two main ways that words can be built up of many morphemes. Agglutinative languages build words by "gluing" morphemes together essentially unchanged. Fusional languages build words by "squishing" morphemes together, often changing the morphemes in the process. European languages tend to be fusional languages, while Native American languages tend to be highly agglutinative.

Examples of polysynthetic languages include Inuktitut, Mohawk and Basque. French has recently been reclassified as polysynthetic: according to some linguists, a phrase like je ne me le lui suis pas? alle is one word because the italicised clitics are actually word inflections. If this is true, French is thus far and away the most synthetic Indo-European language.