When "wax" refers to talk about something in an emotional way When "wax" refers to talk about something in an emotional way, why it will be followed by an adjective rather than an adverb? Thank you. Such as: 1, He waxed lyrical (why not lyrically?) about the skills and commitment of his employees. 2, Her mother waxed eloquent (why not eloquently? ) on the theme of wifely duty.