Question

1.The Reverend Jesse Jackson spoke at the convention.
2.I wear heavy wool socks under my hiking boots.
3.Joel and Tina are participating in the Special Olympics.

Identify prepositional phrase, tell if adj or adverb phrase then word that phrase modifies

1.at the convention-adverb-spoke
2.under my hiking boots-adj-heavy wool
3.in the Special Olympics-adv-participating

Answer 1

1 and 3 are correct.

2. Your prepositional phrase is correct. But -- "under my hiking boots" tells where, so it must be an adverbial phrase modifying "wear." Another way of looking at this is that the phrase can be placed at least three places in this sentence. That fact identifies it as an adverb, modifying the verb.