Indicates a state of questioning.
Interrogative verbs are "why" and "when" and other question words.
After her death, Victor seems to feel remorse and guilt because he is aware of what he did, because of the monster he created two family members are dead. Bu, at one point, these feelings turned into anxiety, it might give the reader the idea that he is impossible to figure out. This attitude might foreshadow what happens in Geneva and his decision of keeping the monster alive. It might be interpreted that more obscure things are about to happen.
C a bird, mainly because a wall, a perch, and light o not have wings. the comparison is made because they want the reader to understand how love can fly