Question

Which word in the sentence does the adverb clause modify?

The day feels warmer since the sun came out.
a. since
b. warmer
c. feels
d. day

Answer 1

The adverb clause here is "since the sun came out" - it gives some information about the timing of the event.

It modifies "feels" (actually I would say that it modifies the phase "feels warmer") - this "feeling" happens since the sun came out, that's when it started!