Reduced Clauses
More explanation (reducing to adj phrase)
Free English Lessons: Reduced Adjective Clauses (thewindlike.blogspot.com)
Reducing Adv Clauses Quiz (ESL Quiz)
ESL Quiz - Reduced Adverb Clauses - Active and Passive Meanings - Quiz 1 (Michael Buckhoff) I- TESL-J (a4esl.org)