HESI Exam Grammar: Key Rules and Concepts You Need to Know

The grammar portion of the HESI exam evaluates your ability to recognize and apply foundational English grammar rules. One of the most important areas to study is the parts of speech. Mastering these will help you analyze and construct grammatically correct sentences, a critical skill for excelling on the exam. In this section, we will explore the primary parts of speech, including verbs, nouns, pronouns, adjectives, and adverbs.

Verbs: Expressing Action or State

A verb is a word that expresses an action or a state of being. Verbs are central to sentence structure, as they describe what the subject is doing or experiencing.

Action verbs describe physical or mental actions. Examples include run, jump, think, and decide. These are easy to spot because they indicate what the subject is actively doing. For example, in the sentence “She reads every day,” the word reads is an action verb.

Linking verbs connect the subject to a subject complement. These do not show action but instead describe a state of being. The most common linking verb is to be (am, is, are, was, were, etc.). For instance, in “He is a doctor,” the verb connects the subject he with the complement a doctor.

Helping verbs, also known as auxiliary verbs, come before the main verb to form a verb phrase. Common helping verbs include have, has, had, will, would, shall, should, do, does, and did. An example is “She is studying for the exam,” where is is the helping verb and studying is the main verb.

Understanding the role verbs play in a sentence will help you recognize proper subject-verb agreement and tense consistency, both important for the HESI exam.

Nouns: Naming People, Places, and Things

A noun is a word that names a person, place, thing, or idea. Nouns can function as subjects, direct objects, indirect objects, and objects of prepositions.

There are several types of nouns:

Common nouns refer to general items, such as a book, a city, or a woman. These are not capitalized unless they begin a sentence.

Proper nouns name specific people, places, or things and are always capitalized. Examples include Sarah, Paris, or Microsoft.

Concrete nouns are things you can see, touch, or measure, like a table or a dog.

Abstract nouns refer to ideas or qualities that cannot be physically touched, such as love, freedom, or wisdom.

Collective nouns represent a group of people or things, such as a team, a class, or a jury.

Being able to identify and correctly use various types of nouns is essential for forming grammatically correct sentences. On the HESI exam, you may be asked to choose the most appropriate noun or correct a misuse of one.

Pronouns: Replacing Nouns

Pronouns are words that replace nouns to avoid repetition and streamline communication. For example, instead of saying “Karen went to Karen’s car,” you can say, “Karen went to her car.” The word her is a pronoun that replaces Karen’s.

There are several types of pronouns:

Personal pronouns refer to specific people or things. Examples include I, you, he, she, it, we, and they.

Possessive pronouns indicate ownership, such as my, your, his, her, its, our, and their.

Reflexive pronouns reflect the action onto the subject, such as myself, yourself, himself, and themselves.

Demonstrative pronouns point to specific things, like this, that, these, and those.

Relative pronouns introduce dependent clauses and relate to a noun previously mentioned. Common relative pronouns include who, whom, whose, which, and that.

Correct pronoun usage includes matching the pronoun with the noun it replaces in both number (singular or plural) and gender when appropriate. Misuse of pronouns is a frequent source of errors, especially in complex sentences, so practicing this concept is crucial.

Adjectives: Describing Nouns

Adjectives are words that describe or modify nouns and pronouns. They provide more detail about a noun’s appearance, quantity, size, shape, color, origin, or other qualities.

For example, in the sentence “The red apple is on the table,” the word red is an adjective describing the noun apple.

Adjectives answer questions such as:

• What kind?

• How many?

• Which one?

Types of adjectives include:

Descriptive adjectives, like tall, blue, or angry, describe a quality.

Quantitative adjectives, like few, many, or several, indicate quantity.

Demonstrative adjectives, like this, that, these, and those, which out specific items.

Possessive adjectives, like my, your, his, and their, show ownership.

Interrogative adjectives, such as which and what, are used in questions.

The HESI exam may test your ability to distinguish between adjectives and other modifiers and to determine the correct placement of adjectives in a sentence. Adjectives typically appear before the noun they modify, but they can also follow linking verbs and act as subject complements.

Adverbs: Modifying Verbs, Adjectives, and Other Adverbs

Adverbs modify verbs, adjectives, or other adverbs. They answer questions like how, when, where, to what extent, and how often. Many adverbs end in -ly, although not all do.

In the sentence “She quickly ran to the store,” the word quickly is an adverb that modifies the verb ran.

When modifying an adjective, adverbs usually come before it: “It was a very hot day.” Here, very modifies the adjective hot.

Adverbs can also modify other adverbs: “She ran incredibly quickly.” The word incredibly modifies the adverb quickly.

Some adverbs do not end in -ly and may be confused with adjectives. For example, the word fast can function as both an adjective and an adverb, depending on its use: “He is a fast runner” (adjective), and “He runs fast” (adverb).

Being able to recognize adverbs and use them appropriately is a valuable skill for the HESI exam, especially when answering questions that require distinguishing between similar-sounding options or improving sentence clarity.

Building Confidence Through Practice

Understanding the parts of speech is not just about memorizing definitions. It’s about being able to apply this knowledge in context. The HESI exam may present sentences and ask you to identify parts of speech or select the grammatically correct sentence among several choices. To build confidence:

• Read sample sentences and underline each part of speech.

• Write your sentences and label each word.

• Practice correcting sentences that contain errors in word usage.

Spending just a few minutes each day focusing on parts of speech will strengthen your grammar skills and improve your performance on the exam. The next section will dive into punctuation and capitalization, helping you master the rules and exceptions that often confuse test takers.

Mastering Punctuation and Capitalization for the HESI Exam

Punctuation and capitalization are critical elements of clear written communication. For the HESI exam, understanding the rules of punctuation and capitalization will help you avoid common errors and choose the most grammatically correct sentence in multiple-choice questions. This section explains the core punctuation marks and capitalization rules you need to know, along with examples to solidify your understanding.

The Purpose of Punctuation

Punctuation provides structure to a sentence. It clarifies meaning, separates ideas, and guides the reader through the writer’s intended rhythm and emphasis. Misusing punctuation can completely change the meaning of a sentence, which is why mastery of these rules is essential for your success on the HESI exam.

End Marks: Periods, Question Marks, and Exclamation Points

Periods (.) mark the end of a declarative sentence—a statement that conveys information.
Example: She studied for the HESI exam.

Question marks (?) are used at the end of interrogative sentences—sentences that ask a question.
Example: Are you ready for the test?

Exclamation points (!) indicate strong emotion or emphasis. They should be used sparingly in formal writing.
Example: You passed the exam!

While all three are used to end sentences, the choice of end punctuation depends on the sentence’s purpose. On the HESI exam, you may be asked to identify which sentence ends with the appropriate punctuation based on its tone and structure.

Commas (,): Clarifying and Connecting Ideas

Commas are among the most frequently used punctuation marks, and they have many roles. Misusing commas can create confusion or result in sentence fragments or run-ons.

Separating elements in a list
Commas are used to separate three or more items in a list.
Example: She brought pencils, paper, and a calculator.
Note: The comma before the final and is called the Oxford comma. While optional in some styles, it is considered standard in academic writing and should be used on the HESI exam.

Joining independent clauses with a conjunction
When two independent clauses are joined by a coordinating conjunction (such as and, but, or, so), a comma is placed before the conjunction.
Example: He studied all week, but he was still nervous.

Setting off introductory elements
Use a comma after introductory words, phrases, or clauses.
Example: After reviewing her notes, she felt more confident.

Setting off nonessential information
Commas are used to enclose words or phrases that are not essential to the meaning of the sentence.
Example: The HESI exam, which is required by most nursing programs, includes a grammar section.

Before direct quotations
Commas introduce direct quotations.
Example: She said, “I’m ready for the exam.”

Overuse or underuse of commas is a common grammatical mistake. Practicing comma placement can improve your sentence structure and help you avoid run-on sentences or comma splices.

Colons (:) and Semicolons (;)

Colons introduce additional information, such as a list, a definition, or an explanation that follows an independent clause.
Example: She needed three things: a pencil, paper, and a calculator.

Do not use a colon after phrases such as or including. A colon must follow a complete sentence.

Semicolons connect two closely related independent clauses that are not joined by a conjunction.
Example: She reviewed her grammar notes; she felt prepared for the exam.

Semicolons can also be used to separate items in a complex list, especially when items already contain commas.
Example: On the trip, she visited Phoenix, Arizona; Las Vegas, Nevada; and Denver, Colorado.

Knowing when to use a semicolon versus a comma can be tricky, but practicing sentence structure will help reinforce these rules.

Quotation Marks (“ ”): Showing Spoken or Cited Words

Quotation marks are used to indicate spoken dialogue, direct quotations, or specific phrases.

Direct quotations
Use quotation marks around the exact words spoken or written by someone.
Example: He asked, “Are you going to the library?”

Punctuation placement
Periods and commas always go inside the closing quotation marks. Question marks go inside the quotation marks if they are part of the quote.
Example: She asked, “Where is the study guide?”

If the question mark is part of the sentence, not the quotation, it goes outside.
Example: Did she say, “We are finished”?

On the HESI exam, you may be asked to identify punctuation errors in quotations or choose the most correct use of quotation marks within a sentence.

Apostrophes (’): Indicating Possession and Contractions

Apostrophes have two main uses: showing possession and forming contractions.

Possession
Add an apostrophe and’s to singular nouns to show ownership.
Example: The student’s book was on the desk.

For plural nouns ending in s, add only the apostrophe.
Example: The teachers’ lounge is upstairs.

For irregular plural nouns that do not end in s, add ’s.
Example: The children’s backpacks were heavy.

Contractions
Apostrophes also indicate omitted letters in contractions.
Example: Can’t (cannot), won’t (will not), she’s (she is or she has)

Avoid confusing contractions with similar possessive pronouns.
Example: It’s (it is) vs. its (possessive form of it)

The HESI exam often tests your ability to distinguish between possessive nouns, possessive pronouns, and contractions.

Capitalization Rules: Knowing When to Use Uppercase Letters

Capitalization gives structure and formality to writing. Knowing the rules of capitalization helps avoid errors that can distract from meaning.

Start of sentences
Always capitalize the first word in a sentence.
Example: Grammar is important on the HESI exam.

Proper nouns and titles
Capitalize specific names of people, places, organizations, and specific titles.
Example: Mary, California, The American Red Cross, President Lincoln

Days, months, and holidays
Capitalize days of the week, months, and names of holidays.
Example: Monday, July, Thanksgiving

Do not capitalize seasons unless they are part of a proper noun.
Example: I love summer.
Example: The Winter Olympics were held in February.

Titles before names
Capitalize a title when it comes before a name.
Example: Dr. Smith, Professor Johnson

Do not capitalize a title when it stands alone or follows a name.
Example: The professor gave a lecture.
Example: Sarah Johnson, a nurse practitioner, led the session.

The pronoun “I”
Always capitalize the pronoun I.
Example: He and I studied together.

On the HESI exam, capitalization errors may be subtle. You could be asked to identify the sentence with incorrect capitalization or to edit a sentence for proper formatting.

Practice Strategies for Punctuation and Capitalization

To reinforce your understanding of punctuation and capitalization:

• Read well-edited writing and observe punctuation and capitalization patterns.

• Practice rewriting sentences with incorrect punctuation or capitalization.

• Create your sentences and self-check them using grammar rules.

Paying attention to the structure of written English in your reading and writing will help you internalize these rules. Punctuation and capitalization may seem minor, but they greatly impact the clarity and correctness of your writing. On the HESI exam, strong grammar skills can make the difference between a correct and incorrect answer.

Mastering Word Usage for the HESI Exam

Correct word usage is one of the most tested areas in the grammar portion of the HESI exam. While many English words sound alike or look similar, their meanings and uses can be quite different. The exam may include questions that test your ability to distinguish between homophones, commonly confused words, and the correct use of comparative and quantitative expressions. This section covers these critical elements in detail.

Understanding Homophones and Confused Word Pairs

Homophones are words that sound the same but have different meanings and spellings. These are common sources of error in writing and are frequently tested on the HESI exam. Let’s look at some of the most important pairs to study.

Their, There, and They’re

There is a possessive pronoun, showing ownership.
Example: Their books are on the desk.

It refers to a place or position, or is used to introduce a sentence.
Example: The papers are over there.
Example: There is a quiz tomorrow.

They’re is a contraction of they are.
Example: They’re going to the library.

Make sure to look carefully at the sentence to determine whether the word should indicate ownership, a location, or a contraction.

Your vs. You’re

Yours is a possessive pronoun.
Example: I found your notebook.

You’re is a contraction of you are.
Example: You’re doing great on your grammar practice.

Mixing up these two is very common. A helpful strategy is to try substituting you are into the sentence. If it doesn’t make sense, the correct word is your. It’s vs. It’sIts is a possessive pronoun meaning belonging to it.
Example: The dog chased its tail.

It’s a contraction of it is or it has.
Example: It’s raining outside.
Example: It’s been a long day.

Even though possessives usually use an apostrophe, it’s an exception. If you can say it is in place of the word, then use its.

Other Commonly Confused Words

In addition to homophones, English contains many word pairs that are similar in spelling or pronunciation but have different meanings.

Accept vs. Except

Accept is a verb meaning to receive or agree to.
Example: I accept your apology.

Except is usually a preposition meaning to exclude.
Example: Everyone is coming except Tom.

To remember the difference, think of accept as an action and except as an exclusion.

Affect vs. Effect

Affect is typically a verb meaning to influence.
Example: The weather can affect your mood.

Effect is usually a noun meaning the result or outcome.
Example: The medicine had a calming effect.

A quick test: If you’re talking about an action, use affect. If you’re referring to a result, use effect.

Advice vs. Advise

Advice is a noun meaning a suggestion or recommendation.
Example: He gave me good advice.

Advise is a verb meaning to give guidance.
Example: She advised me to study harder.

The ending -ice refers to a thing, while -ise refers to an action.

Definitely vs. Defiantly

Means certainly or without a doubt.
Example: I want to pass the exam.

Defiantly means rebelliously or boldly resistant.
Example: She refused to answer.

These two are often confused in writing due to spelling similarities, but their meanings are quite different. Use context clues to determine which fits the sentence logically.

Comparative and Superlative Forms

Comparative and superlative forms are used to show degrees of comparison between two or more things. These forms are created by adding -er or -est to the end of adjectives, or by using more and most with longer adjectives.

Using -er and -est

Use -er when comparing two things.
Example: This test is harder than the last one.

Use -est when comparing three or more things.
Example: That was the hardest exam of the semester.

If the adjective is one syllable, typically add -er or -est. If the adjective has two or more syllables, use more or most.

Example:
This essay is more detailed than the last.
She is the most talented student in the class.

Using both forms at once is incorrect:
Incorrect: This is the easiest question.
Correct: This is the easiest question.

Less vs. Fewer

Understanding the difference between less and fewer is important for correct grammar and clarity.

Less is used for things that cannot be counted individually or measured in discrete units (non-count nouns).
Example: There is less water in the bottle.

Fewer is used for things that can be counted (count nouns).
Example: She has fewer books than he does.

One way to remember this rule is:
Use fewer things you can count (cookies, pencils, students).
Use less for things you measure (milk, time, money).

Incorrect: I have fewer apples than you.
Correct: I have fewer apples than you.

Practice Identifying Correct Word Usage

To prepare for the HESI exam, practice spotting these word errors in sentences. Here are some sample corrections that mirror the style of the exam:

Incorrect: You’re going to do great on the exam.
Correct: You’re going to do great on the exam.

Incorrect: The dog wagged its tail.
Correct: The dog wagged its tail.

Incorrect: She had fewer pens than he.
Correct: She had fewer pens than he.

Incorrect: The storm affected the power lines.
Correct: The storm affected the power lines.

Tips for Mastering Word Usage

Improving word usage comes down to practice and attention to detail. Here are strategies to help solidify these concepts:

• Read your writing aloud to catch incorrect word choices.

• Quiz yourself with flashcards for commonly confused words.

• Substitute longer forms for contractions to see if they make sense.

• Group similar word pairs together and review them as a category.

The HESI exam will often present subtle distinctions between choices. The better you understand these commonly confused words, the easier it will be to pick the right answer.

Understanding Sentence Structure for the HESI Exam

Sentence structure is one of the more advanced grammar topics covered on the HESI exam. Unlike basic grammar questions, sentence structure questions often ask you to identify not just correct sentences, but the most effective or clearest way to express an idea. That means more than one answer may be technically correct, but one will be considered the best. To answer these questions correctly, you need a strong understanding of sentence components, clause relationships, punctuation use, and style clarity.

The Parts of a Sentence

Every complete sentence contains two basic elements: a subject and a predicate.

Subject
The subject is the person, place, thing, or idea that is performing the action or being described.
Example: The nurse took the patient’s temperature.

Predicate
The predicate tells what the subject does or is. It includes the verb and any objects or modifiers.
Example: The nurse took the patient’s temperature.

Without both elements, a sentence is incomplete. The HESI exam may ask you to identify or fix sentence fragments that are missing a subject, verb, or both.

Independent and Dependent Clauses

A clause is a group of words that contains both a subject and a verb.

Independent clauses can stand alone as complete sentences.
Example: She reviewed her notes.

Dependent clauses cannot stand alone. They depend on the main clause to complete the meaning.
Example: Because she reviewed her notes
(This is not a complete sentence on its own.)

When writing complex sentences, it’s important to recognize the difference between these two clause types so you can properly connect them using punctuation and conjunctions.

Sentence Types

English sentences come in four basic types, each serving a different function.

Simple sentences
It contains one independent clause.
Example: The student studied all night.

Compound sentences
Contain two independent clauses joined by a coordinating conjunction (for, and, nor, but, or, yet, so).
Example: She was tired, but she kept studying.

Complex sentences
It contains one independent clause and one or more dependent clauses.
Example: Although she was tired, she kept studying.

Compound-complex sentences
Contain two or more independent clauses and at least one dependent clause.
Example: Although she was tired, she kept studying, and she finished all her practice questions.

The HESI exam may include questions that ask you to revise sentences to improve clarity and structure or identify the sentence type based on its clauses and punctuation.

Run-On Sentences and Comma Splices

A run-on sentence occurs when two independent clauses are joined without appropriate punctuation or a conjunction.
Incorrect: She was tired, but she kept studying.

A comma splice is a specific type of run-on where two independent clauses are joined with only a comma.
Incorrect: She was tired, but she kept studying.

These errors can be corrected in several ways:

• Use a period to separate the clauses:
  She was tired. She kept studying.

• Use a semicolon:
  She was tired; she kept studying.

• Use a comma with a coordinating conjunction:
  She was tired, but she kept studying.

• Make one clause dependent:
  Although she was tired, she kept studying.

Identifying and fixing these common sentence structure errors is a key part of the HESI grammar section.

Sentence Fragments

A fragment is an incomplete sentence that lacks either a subject, a verb, or a complete thought.
Incorrect: While studying for the HESI exam.

This fragment can be corrected by adding an independent clause.
Correct: While studying for the HESI exam, she made flashcards.

Watch for dependent clauses that are mistakenly used as complete sentences. They often begin with subordinating conjunctions such as because, although, if, while, when, or since.

Parallel Structure

Parallel structure means that elements in a sentence that are similar in function should also be similar in form. This makes sentences easier to read and understand.

Incorrect: She enjoys reading, to jog, and cooking.

Correct: She enjoys reading, jogging, and cooking.

In the correct version, all the items in the list follow the same grammatical pattern (gerunds ending in -ing). Parallel structure is especially important in lists, comparisons, and items joined by conjunctions.

The HESI may ask you to choose the most grammatically balanced sentence from a group of similar options, so look for consistent patterns.

Sentence Clarity and Conciseness

On the HESI, some questions require you to pick the clearest or most effective sentence, even when more than one is grammatically correct. Clarity and conciseness often make the difference between a correct and incorrect answer.

Consider these two sentences:

• It was hot, so Cindy and Greg went to the pool.

• Cindy and Greg went to the pool; it was hot.

Both are grammatically correct, but the first is clearer and more logically ordered. It explains cause and effect in a way that’s easier to follow.

When comparing sentence options:

• Avoid wordiness or unnecessary repetition.

• Choose active voice over passive voice when possible.

• Ensure modifiers are placed near the words they describe.

Example of a misplaced modifier:
Incorrect: Running to the bus stop, the rain started falling.
Correct: Running to the bus stop, she got soaked by the rain.

The incorrect sentence implies that the rain was running, which creates confusion.

Active vs. Passive Voice

In active voice, the subject acts.
Example: The doctor prescribed medication.

In passive voice, the subject receives the action.
Example: Medication was prescribed by the doctor.

Active voice is preferred in most writing because it is more direct and clear. Passive voice is not always incorrect, but it can make sentences less engaging or more difficult to follow. On the HESI exam, choose the sentence that expresses the idea most directly and clearly, unless the passive voice is more appropriate for the context.

Sentence Variety

Using a mix of sentence types and lengths can improve writing quality and reader engagement. While this is more relevant in essay writing, sentence variety can also be a factor in choosing between grammatically correct options on the HESI.

For example:

• Short, simple sentences create emphasis or urgency.

• Longer, complex sentences convey detailed or layered information.

The exam may ask which sentence flows best in a given context. Sentence variety, logical progression, and clarity will guide you toward the best choice.

Final Tips for Sentence Structure Questions

• Read all answer choices fully before selecting one.

• Look for subject-verb agreement and proper punctuation.

• Eliminate fragments, run-ons, and awkward phrasing.

• When all options are grammatically correct, choose the most concise and clear.

• Practice editing poorly written sentences to reinforce your understanding.

Mastering sentence structure is one of the most important parts of preparing for the grammar section of the HESI exam. It pulls together everything you’ve learned about grammar, punctuation, and word usage into complete, polished writing.