Identify the word which the italicized adverb clause modifies. john finished his work quickly after taking a break.

Adverb clause is a group of words that function as an adverb and can tell when, where, why, and how are verbs, adverbs, and adjectives. 
 
The adverb clause in this sentence is "after taking a break" and it modifies the verb quickly. It tells us when the work is done quickly. 

This is love because he’s saying she walks in beauty so that refers love or likening someone