[suteja]

I have some confusion regarding adverb clauses.

I understand that adverb clause modifies a verb/adverb/adjective.

"I am so hungry that I can finish the whole food." I think that "that I can finish the whole food" is the adverb clause, however I do not know what it modifies in the main clause.

"He appeared for the test though he was ill." I think that "though he was ill" is the adverb clause, again, what does it modify in the main clause?

"She was as pretty as a rose." Here what does the adverb clause "as a rose" modify in the main clause?

Thanks in advance.