English Grammar - Part of Speech

Part of speech is a structure of a sentence. Full in the end can't make a sentence but because the words need to be arrange in proper order so it will be a correct sentence.
Example = "Birds in the sky fly" but it need to be proper so = "Bird fly in the sky"
We need to decribe about more about the "birds" inside the sentence so example, where the bird fly? so we said it "Bird fly in the sky" but still we need to describe it a little more detail, "the red birds fly fast in the sky with their wings", it will be a proper sentence.

"The red bird fly fast in the sky with their wings"

"red"=adjective "Bird" = Noun "fly" = Verb "fast" = Adverb
and still we need to put pronouns = "their", "In" and "with" shows the relationship and their called = preposition. "The" = Article and it important to put in a sentence.

So here are the list so it will be more easy to understand =
Part of speech

Birds = Noun
fly= verb
fast=adverb
red = adjective
the=article
their=pronoun
in & with = preposition

The red Bird fly fast in the sky