Japanese language have a special group of words which repeat mostly two syllable word like pera pera, para para, jito jito, suku suku, aka aka, zuki zuki – you can name it, that are used adverbially.
They look like onomatopoeias, but they are not. They don’t reflect any sound, and they are all used adverbially, not as interjection.
I am curious to know what is a grammatical terminology in both Japanese and English to call such a group of words. Would you please teach me?