The old firefighter stood over the smoking ruins, his senses alert to any sign of another flare-up . His subordinates, their faces sweat-streaked and smudged with ash , leaned heavily against the firetruck. It is not unusual for the information supplied in the absolute phrase to be the most important element in the sentence. The new recruits stood in one corner of the gym, their uniforms stiff and ill fitting, their faces betraying their anxiety. It might be useful to review the material on Misplaced Modifiers because it is important not to confuse an absolute phrase with a misplaced modifier.
Infinitive phrases can act as adjectives, adverbs, and nouns.
Her plan to subsidize child care won wide acceptance among urban politicians. She wanted to raise taxes . To watch Uncle Billy tell this story is an eye-opening experience. To know her is to love her . Juan went to college to study veterinary medicine .