How do you differentiate between nouns, verbs, adverbs and adjectives?

Hint:Parts of speech are essential elements of a language which describes different categories of different types of words. A noun, verb, adverb and adjective are parts of speech. We will have a better understanding of these in the complete answer below.

Complete answer:
Let us discuss all the above parts of speech individually in detail to figure out the correct answer with the help of the above stated hint.
A noun is the name of a person, place or thing. Example: Girl, boy, chair, book, Tokyo, beach etc. A noun can be anything and it acts as the subject in a sentence.
A verb is defined as an action word that describes a particular action being done. Verbs describe things that nouns do. Example: run, eat, sleep, think etc.
An adverb is a word that adds more information to a verb. It describes the action being taken place. Adverbs often end with the suffix -ly. Example: quickly, softly, eagerly, roughly etc.
An adjective is a word that gives us more information about a noun. It describes how or what a noun is. Adjectives are quality words that describe the quality of the noun. Example: beautiful, smart, intelligent, easy, simple etc.

Many words can be a noun, a verb, an adverb, an adjective depending upon its ending.
Example:-
Noun- action
Verb- act
Adverb- actively
Adjective- active

Note:Parts of speech are used to categorise different types of words. Each category has a different usage and significance in writing. Example: Ram ran quickly as he is a fit athlete. In the given sentence, the noun is Ram, the verb is run, the adverb is quickly and the adjective is fit.