one: It’s well-known that the subjects of different verbs in different contexts can take subjects that have different semantic roles.
For example, in the sentence “Jill ate a hamburger,” “Jill” stands for an agent.
But in the sentence “Jill saw a nice sunset,” “Jill” stands for an experiencer.
two: The subjects of the following sentences stand for experiencers as well.
“Jack smelled smoke.”
“The dog heard a loud noise.”
“Henry felt the cold air.”
three: QUESTION: Are the subjects of the following sentences agents, experiencers, both, or something else?
“Lily watched ants for fun.”
“Jack was reading the book.”
“The boy listened for the train.”