1. I don't know anyone in my class.
2. In my class, I don't know anyone.
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In #1, what is the part of speech of 'in my class'? Does 'in my class' modify 'anyone' or 'know'? In #2, 'In my class' is an adverbial phrase, right?
"in my class" is a prepositional phrase:
in = preposition
my = possessive pronoun (modifying "class")
class = noun, object of the preposition "in"
In both sentences, the phrase modifies "anyone."