Although they have different emphasis, the common and key characteristic is that by definition, all hedges make things fuzzy in some sense for the purpose of communicative effects.

2.1.2 The Classifications of Hedges

Due to different research perspectives, hedges are pided by different categorizing means and standards. 

L.A. Zadeh is regarded as the first person to make the classification abroad. Zadeh’s fuzzy set theory counts as the origin of hedges study. He pides hedges into four categories:

“(1) Some adjectives and adverbs such as sort of, often, almost, etc.

 (2) Words with suffixes such as -ish, -likely, -ly, etc.

 (3) Phrases such as so...as to, as if, etc. 

 (4) The terms such as I think, I wonder, as far as I know, etc.” (qt. He Ziran, 1985: 28)