Frequency adverbs are followed by verbs, indicating the frequency of actions. For example, "he often goes to the library to read books", in which "often" is an adverb of frequency, followed by the verb "go".

Frequency adverbs can indicate the number and frequency of actions. Common frequency adverbs are "occasionally", "sometimes" and "almost". Using frequency adverbs can express the frequency of actions more accurately and make sentences more clear and specific.