If a noun is a person, place or thing, then is a pronoun a professional person, place or thing? Not quite, but the effective use of nouns and pronouns can help a writer look like a pro rather than an amateur. We naturally substitute pronouns for nouns in speech without much thought, so the correct use of these parts of speech is easy when you know a few simple rules.
First -- be it person, place or thing -- a noun is the heart of a sentence. Nouns describe people, such as women, men, daughters, sons, waiters, mechanics and writers. Nouns tell where the action is happening. Parks, libraries, outer space, stateside, highways or downtown are both places and nouns. Nouns refer to things, such as cars, wrenches, diaries, helmets, ideas, sand and cattle. At least one noun is the subject of a sentence, and is the reason the sentence was written in the first place.
Next, if the overuse of the word "noun" in the previous paragraph has you yearning for words like "it" and "they," then you possess an intrinsic knowledge of pronouns. Think of them as substitute teachers called in when the class needs a break from the original instructor. Pronouns include words such as I, you, he, she, it, them, they, we, you, themselves, himself and us, and are used to prevent word repetition and to shorten sentences .
A friendly relationship exists between nouns and pronouns as they work together to form clear sentences. Pronouns are used to replace nouns the second time they are used in a sentence or paragraph. For example, "The girl bought the girl a soda," becomes a more clear sentence when the pronoun "herself" is substituted, "The girl bought herself a soda." The key to a successful noun-pronoun partnership is to keep them both singular or both plural: "The dog chased its tail," or "The dogs chase their tails," are acceptable. "The dog chased their tail," is unacceptable because "dog" is singular and "their" is plural.
Indefinite pronouns don't refer to a specific noun, hence the name. They may be anyone, anything, everyone, everything, no one, neither, both, several or many. Demonstrative pronouns identify a particular noun and come first in a sentence. "Those are my shoes," pairs the pronoun "those" with the noun "shoes." The pronoun is deemed demonstrative because it demonstrates knowledge of the noun. And finally, an interrogative pronoun asks a question and is used at the beginning of a sentence.