This document discusses different types of adverbials. It explains that adverbials can modify verbs, adjectives, and other adverbs. Adverbials include one-word adverbs, adverb phrases using words like "really" and "honestly", prepositional phrases functioning as adverbs like "on Tuesday", and adverb clauses introduced by words like "since" and "when". The same word can sometimes function as an adverbial or adjectival depending on the context.