Eight parts of speech is very important in English. If you know exactly how to use it, you'll find English isn't difficult as you thought.
At first, I don't know what coordinating conjunctions are. But I found that there's a shortcut for these words. It's called F.A.N.B.O.Y.S which is easy to remember.
And I also found that auxiliary verb and helping verb is the same.
You'll find that every English sentences contains eight parts of speech.