Agglutination is when a language can add many separate little pieces onto words each giving some extra meaning. A language with a lot of agglutination is agglutinative. Fusion is when each bit added to words means many different things at the same time. A language that uses fusion more is fusional.
An example of agglutination in English could be “antidisestamblishmentarianism”, where all those small pieces are added to the one word “establish”. However this is uncommon in English, and English is not an aggultinative language. An example of fusion could be the “-s” at the end of “sees” in “he sees”, showing that it is both he/she/it doing it, and that it is in present tense. This isn’t the best example, since English is not very fusional at all.
