There are eight parts of speech in the English language: noun, pronoun, verb, adjective, adverb, preposition, conjunction, and interjection. The part of speech indicates how the word functions in meaning as well as grammatically within the sentence.
That's right. Noun shows the name of sth,pronoun replaces the noun,verb shows actions,adjective modifies the noun or pronoun,preposition shows the relationship of a word with a sentences ,conjunction links phrases, clauses and sentences together, interjections shows actions.