This document discusses reducing adverb clauses to modifying adverbial phrases in English. It provides examples of changing time clauses introduced by words like after, before, while, and since. It also discusses expressing simultaneous events using modifying phrases with -ing rather than while clauses. Additionally, it covers expressing cause and effect relationships and using upon+-ing phrases, which have the same meaning as when clauses. The document aims to teach how to construct modifying adverbial phrases that convey the same meanings as various types of adverb clauses.