It is really important to know the eight parts of speech because we can't write a sentence without them. Oops! I have already used all of them.
Nouns - eight, parts, speech, sentence
Pronouns - it, we, them
Verbs - is, know, can't, write, have, used
Adjectives - important
Adverbs - really, already
Prepositions - to, without, of
Conjunctions - because
Interjections - Oops
Articles - the, a