In Japanese grammar, sound symbolic words primarily function as adverbs, though they can also function as verbs (verbal adverbs) with the auxiliary verb , often in the continuous/progressive form , and as adjectives (participle) with the perfective form of this verb . Just like ideophones in many other languages, they are often introduced by a quotative complementizer . Most sound symbolic words can be applied to only a handful of verbs or adjectives. In the examples below, the classified verb or adjective is placed in square brackets.