1) Adverbs of manner typically describe how an action is performed and are often formed by adding "-ly" to an adjective.
2) Some adjectives become adverbs with spelling changes like "-le" to "-ly" or "-ic" to "-ically".
3) Adverbs like "fast", "hard", and "late" have the same form as their related adjectives.
4) Prepositional phrases or nouns can also be used as adverbs of manner when there is no simple adverb form.