Halliday & Matthiessen (2004: 268):
Quality is typically expressed by an adverbial group with an -ly adverb as Head; the interrogative forms is how? or how … ? with an appropriate adverb. Less commonly, Quality is realised by a prepositional phrase. The general type is one where the preposition is in or with and the Head/Thing of the nominal group is the name of ‘manner’, either manner or way, or of a qualitative dimension such as speed, tone, skill, ease, difficulty, term; but phrasal expressions of Quality also include more specific types, such as specifications of the manner of movement.