Parts of Speech are fundamental on forming sentence, they show the relatnship between words within a sentence.
E.g.: nouns: computer, Mozambique, Jhon, etc.
adjectives: cute, pretty, happy
verb: 'to clean','to write','to read',etc
adverbs: quickly, slowly, early,ect
conjunctions: and, nor, but, for, etc
preposition: in, on, at, under, etc
interjection: oh! duh! aw!etc
pronouns: I, you, he, she, it, etc
I use my cute computer for to write my letter. It is on table and it works slowly