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Definition And How Do I Know If Its One Of The Following.. :)
Noun: person, place or thing. Functions as a subject or as an object.
Verb: action or state. Changes form in person and tense.
Adverb: modifies a verb or an adjective. Answers the questions why, how, when, where?
Adjective: modifies a noun. Answers the question what kind of? Can come either before a noun or after a noun.