Question

In the sentence "Let's walk around.", is around a noun? Also, in the sentence "Let's walk around the block.", what part of speech is around?

Answer 1

Many words can be identified as adverbs AND prepositions, depending on how they're used in the sentence.

In your first sentence, "around" is an adverb. It's telling <b>where</b> the verb is taking place.

In the second sentence, "around" is a preposition; the entire prepositional phrase is "around the block" and it's being used adverbially.

http://grammar.ccc.commnet.edu/grammar/adverbs.htm

http://grammar.ccc.commnet.edu/grammar/prepositions.htm

Answer 2

No, "around" tells where you are walking, so it modifies the verb.

"Around the block" is a prepositional phrase telling where you are walking.... so around is a what ?