preposition
Around the country is a prepositional phrase.
Corner is a noun in the sentence "Around the corner was her mom."
Round is an adjective in that sentence.
part of speech
The part of speech for this particular word is a noun.
The word "but" is a conjunction, a word that joins groups of words around it together.
adverb
what part of speech is work
what part of speech is beneath
the part of speech sashay is a averb
Did is a verb, and not is an adverb. Didn't is not any part of speech. It's a contraction of did and not.