A part of speech is the role a word plays in a sentence.
Example:
-
Noun → names a person, place, thing, or idea.
Example: "Cat" -
Verb → shows an action or state.
Example: "Run" -
Adjective → describes a noun.
Example: "Beautiful" -
Adverb → describes a verb, adjective, or another adverb.
Example: "Quickly"
So, each word in a sentence belongs to a part of speech depending on how it’s used.