Final answer:
In the sentence 'Colleen went to bed early since she had a test tomorrow,' the adverb clause is 'since she had a test tomorrow,' the subordinating conjunction is 'since,' and this clause modifies the verb 'went'.
Step-by-step explanation:
In the sentence, "Colleen went to bed early since she had a test tomorrow," we can identify the following elements:
- Adverb clause: "since she had a test tomorrow"
- Subordinating conjunction: "since"
- Word(s) modified: The adverb clause modifies the verb "went," telling us the reason why Colleen went to bed early.
An adverb clause is a dependent clause that provides information about the verb it modifies, indicating time, place, condition, contrast, etc. A subordinating conjunction connects a subordinate clause to the main clause and indicates the relationship between them. And the modifying words are given more information by the adverb clause, clarifying the action or state described by the verb.