An agglutinative language is a type of synthetic language with morphology that primarily uses agglutination: words may contain different morphemes to determine their meaning, but each of these morphemes (including stems and affixes) remains in every aspect unchanged after their union, thus resulting in generally easier deducible word meanings if compared to fusional languages, which allow modifications in the phonetics and/or spelling of one or more morphemes within a word, generally for shortening the word on behalf of an easier pronunciation. Examples: Japanese language, Korean language, Mongolic languages, Tungusic languages, Turkic languages, Uyghur languages, Armenian language, Athabaskan languages.

A fusional (inflecting) language is a type of synthetic language, distinguished from agglutinative languages by their tendency to overlay many morphemes to denote grammatical, syntactic, or semantic change. For example, the Spanish language verb comer (“to eat”) can be expressed in first-person past perfect tense as comí, a word formed removing the “-er” suffix of the verb and replacing it by “-í”, that indicate such specific meaning. Examples of fusional Indo-European languages are: Sanskrit, Greek (classical and modern), Latvian, Pashto, Polish, Russian, German, Icelandic, Croatian, Serbian, Czech, French, Irish, Albanian, Latin, Punjabi, and the Iberian Romance dialect continuum.

An agglutinative language is a type of synthetic language with morphology that primarily uses agglutination: words may contain different morphemes to determine their meaning, but each of these morphemes (including stems and affixes) remains in every aspect unchanged after their union, thus resulting in generally easier deducible word meanings if compared to fusional languages, which allow modifications in the phonetics and/or spelling of one or more morphemes within a word, generally for shortening the word on behalf of an easier pronunciation. Examples: Japanese language, Korean language, Mongolic languages, Tungusic languages, Turkic languages, Uyghur languages, Armenian language, Athabaskan languages.

A fusional (inflecting) language is a type of synthetic language, distinguished from agglutinative languages by their tendency to overlay many morphemes to denote grammatical, syntactic, or semantic change. For example, the Spanish language verb comer (“to eat”) can be expressed in first-person past perfect tense as comí, a word formed removing the “-er” suffix of the verb and replacing it by “-í”, that indicate such specific meaning. Examples of fusional Indo-European languages are: Sanskrit, Greek (classical and modern), Latvian, Pashto, Polish, Russian, German, Icelandic, Croatian, Serbian, Czech, French, Irish, Albanian, Latin, Punjabi, and the Iberian Romance dialect continuum.