Absolute phrases are made of nouns or pronouns followed by a participle and any modifiers of the noun or pronoun. Absolute phrases contain a subject (unlike participial phrases), and no predicate. They serve to modify an entire sentence. Examples:
Joan looked nervous, her fears creeping up on her. noun/subject: her fears participle: creeping modifier: up on her absolute phrase: her fears creeping up on her
Tom paled when he came home, his mother standing in the doorway. noun/subject: his mother participle: standing modifier: in the doorway absolute phrase: his mother standing in the doorway