Understand that a noun is a word that represents a person, place, thing or idea. Generally, this is the first step to identifying nouns in a sentence. However, it is important to look at these words in context. Some nouns may act as other parts of speech in the sentence.
Recognize the difference between proper nouns and common nouns. Proper nouns refer to a particular person or place. They are always capitalized. Examples are: Barack Obama, Washington or the Eiffel Tower.
Know that common nouns are either concrete like the words table, lizard and oxygen, or abstract such as hatred, capitalism or length.
Realize that a noun may act as a different part of speech within a sentence. The easiest example is a possessive noun that acts as an adjective. For example, in the sentence: "Sara could not find Paul's book." Sara and book are nouns, but "Paul's" acts as an adjective modifying the book. It helps identify the book, it is not a separate thing.
Understand that pronouns are words that replace nouns. Like nouns they identify a person, place, thing or idea. They take the place of other nouns to prevent speech from becoming repetitious.
Identify the different categories of pronoun. Personal pronouns refer to specific people, places and things and take the place of proper nouns. "I", "we" and "she" are subjective personal pronouns. "Us", "you" and "them" are objective personal pronouns. Possessive pronouns are words like mine, yours and theirs. Indefinite pronouns are third-person pronouns such as anyone, nobody or either. Reflexive pronouns add emphasis so they do not appear alone in a sentence. An example is "Bill Clinton himself called to ask her to come to the meeting." Relative pronouns like "that" and "which" begin a clause that refers to a noun in a sentence. Depending upon the context, "that" can also be a demonstrative pronoun. In the sentence "That is the perfect dress." "That" is a demonstrative pronoun.
Memorize common pronouns. This is the easiest way to ensure that you separate nouns from pronouns. The list is not that long and is easily understood because you use pronouns so much in every day speech.
Understand that verbs are words used to identify an action or state of being.
Differentiate between action and linking verbs. These are also called transitive and intransitive verbs.
Recognize that action verbs can describe physical, mental or emotional actions. Examples are: run, understand, open and increase. Linking verbs link the subject to the verb.
Know that linking verbs modify the subject and do not have a direct object. Forms of the verb "to be" are the most common linking verbs. Other verbs such as "improve" or "feel" are either transitive or intransitive depending upon the context. If a verb requires a direct object it is an action or transitive verb. In "The actor left the stage," the action verb is "left." In "Sharon left" it is an intransitive or linking verb.