"It" is always a pronoun, unless within quotation marks.
subject
noun
Noun, and part of an adjectival phrase.
regular speech
I believe it would be an adjective.
An auxiliary verb.
it depends what word it is it could be any part of speech depending on the sentence
The action in a sentence is the part of speech known as a verb.
Past is being used as a noun in that sentence.
In the sentence "The time is up," the word "up" functions as an adverb. It indicates the completion or expiration of time, modifying the verb "is."
The part of speech for "gliding" is a gerund, which functions as a noun in a sentence.
The part of speech of "correct" in this sentence is an adjective.