How can we differentiate between an adverbial phrase and a prepositional phrase?
1. I saw the movie on Friday.
2. Holmes is on the bed.
In 1st sentence, it is clear that "on Friday" is qualifying "saw" and is an adverbial phrase. But in the second sentence, "on the bed" is also qualifying "Holmes". But usually such phrases are regarded as prepositional phrase. So, how could be differentiate between the two.
Is it possible for a clause to be both (adverbial phrase and prepositional phrase) at the same time?