Answer:
1. Near
Preposition: He lives near the grocery store.
Adverb: Come near to the table.
2. Across:
Preposition: He drove across the city.
Adverb: We can't swim across quickly.
3. Out
Preposition: She pushed him out the door.
Adverb: We will eat out tonight.
4. Aboard
Preposition: The breeze blew gently as I went aboard the ship.
Adverb: A few people aboard survived the crash.
5. Within
Preposition: I finished my project within a month.
Adverb: She heard a loud voice from within.
Explanation: A preposition describes the relationship between two things, whereas an adverb describes or modifies an action. This is the main distinction between a preposition and an adverb. Prepositions include words like "on" and "around," which are used to indicate the relationship between two things or concepts in space or time. Contrarily, adverbs are used to describe a single word or object; they frequently modify verbs, adjectives, and other adverbs. They contain words like "quickly" and "very." However, because a prepositional phrase can function as an adverb in some sentences, the distinction between a preposition and an adverb can sometimes be unclear.