Adjectives of Purpose: A Comprehensive Grammar Guide

Understanding adjectives of purpose is crucial for constructing clear and effective sentences in English. These adjectives specify the intended function or use of a noun, adding precision and depth to your writing and speaking.

This guide provides a thorough exploration of adjectives of purpose, covering their definition, types, usage rules, and common mistakes. Whether you’re an English language learner or a seasoned writer, mastering adjectives of purpose will significantly enhance your communication skills by allowing you to convey the intended function or use of an object or concept more precisely.

Table of Contents

• Definition of Adjectives of Purpose
• Structural Breakdown
• Types and Categories of Adjectives of Purpose
• Gerunds as Adjectives of Purpose
• Infinitives as Adjectives of Purpose
• Examples of Adjectives of Purpose
• Examples with Gerunds
• Examples with Infinitives
• Usage Rules for Adjectives of Purpose
• Word Order
• Prepositions with Adjectives of Purpose
• Common Mistakes with Adjectives of Purpose
• Incorrect Gerund Usage
• Incorrect Infinitive Usage
• Practice Exercises
• Exercise 1: Identifying Adjectives of Purpose
• Exercise 2: Using Gerunds and Infinitives
• Exercise 3: Correcting Sentences
• Advanced Topics
• Nested Adjectives of Purpose
• Adjectives of Purpose with Abstract Nouns
• Frequently Asked Questions (FAQ)
• Conclusion

Definition of Adjectives of Purpose

An adjective of purpose is a word or phrase that modifies a noun by specifying its intended function or use. It clarifies why something exists or what it is designed to do. These adjectives provide essential information about the noun they modify, making the sentence more precise and informative. Adjectives of purpose are typically formed using gerunds (verb + -ing) or infinitives (to + verb) and are crucial for conveying the intended function of an object or concept.

For instance, in the phrase “a sleeping bag,” the word “sleeping” is an adjective of purpose. It tells us the bag’s intended function: to be used for sleeping. Similarly, in “a tool to cut wood,” “to cut” is an adjective phrase of purpose explaining the tool’s intended use. These adjectives are essential for precise communication, helping to avoid ambiguity and ensuring that the listener or reader understands the intended purpose of the noun in question.

Structural Breakdown

Adjectives of purpose can be single words, phrases, or even clauses. Understanding their structure is key to using them correctly.

Typically, they follow the noun they modify, especially when they are phrases or clauses. Single-word adjectives of purpose usually precede the noun.

The structure often involves a combination of nouns, verbs, and prepositions to clearly define the purpose.

For example, consider the phrase “a machine for grinding coffee.” Here, “for grinding” is a prepositional phrase acting as an adjective of purpose. The preposition “for” connects the noun “machine” to the gerund “grinding,” indicating the machine’s intended function. In more complex sentences, adjectives of purpose can be embedded within relative clauses, providing even more detailed information about the noun’s purpose.

Types and Categories of Adjectives of Purpose

Adjectives of purpose can be broadly categorized based on their grammatical form. The two primary categories are gerunds and infinitives, each offering a slightly different nuance in expressing purpose.

Understanding these categories helps in choosing the most appropriate form for a given context.

Gerunds as Adjectives of Purpose

A gerund is a verb form ending in “-ing” that functions as a noun. When used as an adjective of purpose, a gerund describes the activity or function for which something is intended.

Gerunds often follow prepositions like “for” or “in” to clearly indicate purpose. Using gerunds effectively allows for concise and clear descriptions of the intended use of an object or concept.

For example, “swimming pool” uses the gerund “swimming” to describe a pool designed for swimming. Similarly, “a cutting board” uses “cutting” to specify that the board is for cutting.

Gerunds provide a dynamic sense of purpose, emphasizing the action or activity associated with the noun.

Infinitives as Adjectives of Purpose

An infinitive is the base form of a verb preceded by “to.” When used as an adjective of purpose, an infinitive describes the intended action or goal related to the noun. Infinitives often follow nouns directly, providing a clear and direct indication of purpose.

The use of infinitives adds a sense of potential or intended action to the description.

For example, “a book to read” uses the infinitive “to read” to describe a book intended for reading. Likewise, “tools to fix cars” indicates that the tools are meant for fixing cars.

Infinitives provide a sense of potential or intended action, highlighting what the noun is meant to accomplish.

Examples of Adjectives of Purpose

To illustrate the concept of adjectives of purpose more clearly, let’s examine a variety of examples using both gerunds and infinitives. These examples will demonstrate the diverse ways in which adjectives of purpose can be used to specify the intended function or use of a noun.

The tables below provide structured examples for easy comprehension.

Examples with Gerunds

The following table provides examples of adjectives of purpose using gerunds. Notice how the gerunds, often following prepositions, clearly indicate the intended function of the noun.

Noun	Adjective of Purpose (Gerund)	Example Sentence
Baking dish	For baking	She used a baking dish for baking the cake.
Swimming pool	For swimming	The swimming pool for swimming is open until 8 PM.
Reading glasses	For reading	He needs reading glasses for reading the small print.
Walking shoes	For walking	She wears walking shoes for walking in the park.
Writing desk	For writing	The antique writing desk for writing is in the study.
Drinking water	For drinking	This drinking water for drinking is purified.
Cooking oil	For cooking	She bought cooking oil for cooking dinner.
Cleaning supplies	For cleaning	We need cleaning supplies for cleaning the house.
Sleeping bag	For sleeping	He packed a sleeping bag for sleeping on the camping trip.
Fishing rod	For fishing	He took his fishing rod for fishing at the lake.
Cutting board	For cutting	Use a cutting board for cutting vegetables.
Sewing machine	For sewing	The sewing machine for sewing clothes is very old.
Dusting cloth	For dusting	She used a dusting cloth for dusting the furniture.
Ironing board	For ironing	Set up the ironing board for ironing the shirts.
Washing machine	For washing	The washing machine for washing clothes is broken.
Drying rack	For drying	She put the clothes on the drying rack for drying.
Grinding stone	For grinding	The ancient grinding stone for grinding grain is on display.
Holding cell	For holding	The holding cell for holding suspects was empty.
Breathing apparatus	For breathing	The diver used a breathing apparatus for breathing underwater.
Learning center	For learning	The learning center for learning new skills is very popular.
Hiking boots	For hiking	He wore hiking boots for hiking in the mountains.
Climbing gear	For climbing	They packed climbing gear for climbing the cliff.
Painting supplies	For painting	She bought painting supplies for painting the landscape.
Drawing paper	For drawing	He used drawing paper for drawing portraits.
Frying pan	For frying	She used a frying pan for frying eggs.

Examples with Infinitives

The following table provides examples of adjectives of purpose using infinitives. Note how the infinitives directly follow the noun and specify the intended action.

Noun	Adjective of Purpose (Infinitive)	Example Sentence
A tool	To cut	He needs a tool to cut the wire.
A book	To read	She borrowed a book to read on vacation.
Money	To spend	He saved money to spend on a new car.
Time	To relax	She needs time to relax after work.
A place	To study	This is a place to study quietly.
A song	To sing	She chose a song to sing at the concert.
A game	To play	They have a game to play during the party.
A letter	To write	He has a letter to write to his friend.
A problem	To solve	This is a problem to solve with teamwork.
An idea	To consider	She has an idea to consider for the project.
A plan	To execute	They developed a plan to execute the strategy.
A reason	To believe	He has a reason to believe in her.
An opportunity	To seize	This is an opportunity to seize and excel.
A challenge	To overcome	This is a challenge to overcome with perseverance.
A task	To complete	He has a task to complete by tomorrow.
A goal	To achieve	She set a goal to achieve this year.
A question	To answer	There is a question to answer on the test.
A decision	To make	He has a decision to make about his future.
A story	To tell	She has a story to tell about her adventures.
A secret	To keep	They have a secret to keep from everyone.
An agreement	To honor	We have an agreement to honor and uphold.
A contract	To sign	He needs a contract to sign for the new job.
A form	To fill	She has a form to fill out for the application.
A document	To review	He has a document to review before the meeting.
A problem	To address	There is a problem to address in the meeting.

Noun	Adjective of Purpose (Infinitive)	Example Sentence
A puzzle	To solve	This is a puzzle to solve during the break.
A riddle	To answer	He has a riddle to answer for the contest.
A test	To pass	She needs a test to pass for graduation.
A course	To study	He enrolled in a course to study advanced physics.

Usage Rules for Adjectives of Purpose

Using adjectives of purpose correctly involves understanding a few key rules. These rules govern word order, the use of prepositions, and the appropriate choice between gerunds and infinitives.

Adhering to these guidelines ensures clarity and precision in your writing and speech.

Word Order

Generally, adjectives of purpose follow the noun they modify, especially when they are phrases or clauses. Single-word adjectives of purpose, however, typically precede the noun.

This placement helps to clearly connect the adjective to the noun it describes.

Correct: “She needs a tool to fix the car.” (Infinitive phrase follows the noun)
Correct: “He uses a cutting board for vegetables.” (Single-word adjective precedes the noun)
Incorrect: “To fix the car a tool she needs.” (Infinitive phrase incorrectly precedes the noun)

Prepositions with Adjectives of Purpose

Prepositions like “for,” “in,” and “to” often accompany adjectives of purpose, particularly when using gerunds. These prepositions help to clarify the relationship between the noun and its intended function.

Choosing the correct preposition is essential for conveying the intended meaning.

Correct: “This room is for studying.” (Preposition “for” with gerund)
Correct: “He needs materials to build a house.” (Preposition “to” with infinitive)
Incorrect: “This room is studying.” (Missing preposition with gerund)

Common Mistakes with Adjectives of Purpose

Several common mistakes can occur when using adjectives of purpose. These errors often involve incorrect use of gerunds or infinitives, or improper placement of the adjective phrase.

Recognizing and avoiding these mistakes will significantly improve the clarity and accuracy of your communication.

Incorrect Gerund Usage

One common mistake is using a gerund without the necessary preposition or in a context where an infinitive would be more appropriate. This can lead to sentences that are grammatically incorrect or unclear.

Incorrect: “This is a swimming pool exercise.”
Correct: “This is a swimming pool for exercising.” (Gerund with preposition)
Correct: “This is a swimming pool to use for exercise.” (Infinitive phrase)

Incorrect Infinitive Usage

Another frequent error is misusing infinitives, especially by omitting the “to” or using an infinitive where a gerund is required. This can alter the intended meaning of the sentence and create confusion.

Incorrect: “He needs a knife cut the bread.”
Correct: “He needs a knife to cut the bread.” (Infinitive with “to”)
Correct: “He needs a cutting knife for the bread.” (Gerund as an adjective)

Practice Exercises

To solidify your understanding of adjectives of purpose, complete the following practice exercises. These exercises will test your ability to identify and use adjectives of purpose correctly in various contexts.

Answer keys are provided for self-assessment.

Exercise 1: Identifying Adjectives of Purpose

Identify the adjective of purpose in each of the following sentences. Underline the adjective of purpose.

Question	Answer
1. She bought a book to read on her vacation.	to read
2. He uses a cutting board for chopping vegetables.	cutting
3. This is a tool to fix the car.	to fix
4. They need a sleeping bag for camping.	sleeping
5. She has a reason to believe in him.	to believe
6. He needs a pen for writing notes.	writing
7. This is a machine for grinding coffee beans.	grinding
8. I need a cloth for dusting the shelfs.	dusting
9. He has an idea to expand his business.	to expand
10. They built a cabin for hiding from the storm.	hiding

Exercise 2: Using Gerunds and Infinitives

Complete each sentence using either a gerund or an infinitive form of the verb in parentheses to create an adjective of purpose.

Question	Answer
1. He needs a knife __________ (cut) the bread.	to cut
2. She uses a special pan __________ (bake) cakes.	for baking
3. This is a room __________ (study) quietly.	to study
4. They bought new boots __________ (hike) in the mountains.	for hiking
5. He needs time __________ (relax) after a long day.	to relax
6. She uses a machine __________ (wash) her clothes.	for washing
7. They need a special saw __________ (cut) metal.	to cut
8. He wears glasses __________ (read) small print.	to read
9. She uses a board __________ (chop) vegetables.	for chopping
10. They made a tool __________ (dig) in the garden.	to dig

Exercise 3: Correcting Sentences

Identify and correct the errors in the following sentences related to adjectives of purpose.

Question	Answer
1. This is a swimming pool exercise.	This is a swimming pool for exercising.
2. He needs a knife cut the bread.	He needs a knife to cut the bread.
3. She uses a baking dish cook cake.	She uses a baking dish to cook cake. or She uses a baking dish for cooking cake.
4. They bought a sleeping bag camp.	They bought a sleeping bag for camping.
5. He has reason believe in her.	He has a reason to believe in her.
6. I need a pen write notes.	I need a pen to write notes. or I need a writing pen.
7. This machine grinding coffee.	This is a machine for grinding coffee.
8. Can I use a cloth dust the furniture?	Can I use a cloth to dust the furniture? or Can I use a dusting cloth?
9. He had an idea expand his business.	He had an idea to expand his business.
10. They built a cabin hide from the storm.	They built a cabin to hide from the storm. or They built a hiding cabin.

Advanced Topics

For advanced learners, understanding more complex aspects of adjectives of purpose can further refine their language skills. These advanced topics include nested adjectives of purpose and their use with abstract nouns.

Nested Adjectives of Purpose

Nested adjectives of purpose involve multiple layers of modification, where one adjective of purpose modifies another. This can create highly specific and detailed descriptions, but it requires careful construction to avoid ambiguity.

Example: “a tool to sharpen knives to cut meat” (The purpose of the knives is to cut meat, and the tool’s purpose is to sharpen those knives.)

Adjectives of Purpose with Abstract Nouns

Using adjectives of purpose with abstract nouns can add depth and clarity to discussions about concepts and ideas. This involves specifying the intended outcome or function of the abstract noun.

Example: “a strategy to achieve success” (The purpose of the strategy is to achieve success.)

Frequently Asked Questions (FAQ)

Here are some frequently asked questions about adjectives of purpose, along with detailed answers to help clarify any remaining confusion.

1. What is the difference between a gerund and an infinitive as an adjective of purpose?

A gerund (verb + -ing) functions as a noun and typically follows a preposition such as “for” or “in,” emphasizing the activity or function. An infinitive (to + verb) describes the intended action or goal and often follows the noun directly, providing a sense of potential or intended action.

For example, “swimming pool” (gerund) describes a pool for swimming, while “a book to read” (infinitive) describes a book intended for reading.

2. Can adjectives of purpose be used in formal writing?

Yes, adjectives of purpose are appropriate for both formal and informal writing. They provide clarity and precision, which are essential in formal contexts.

However, ensure that the usage is grammatically correct and that the intended meaning is clear.

3. How do I choose between using a gerund or an infinitive as an adjective of purpose?

The choice between a gerund and an infinitive depends on the context and the specific meaning you want to convey. Use a gerund when emphasizing the activity or function, and use an infinitive when highlighting the intended action or goal.

For example, “a room for studying” emphasizes the activity of studying, while “a room to study” emphasizes the intention to study.

4. What prepositions are commonly used with gerunds as adjectives of purpose?

Common prepositions used with gerunds as adjectives of purpose include “for,” “in,” “of,” and “by.” For example, “a tool for cutting,” “a method in solving,” “a way of learning,” and “a means by achieving.”

5. Are there any exceptions to the word order rules for adjectives of purpose?

While adjectives of purpose generally follow the noun they modify, single-word adjectives typically precede the noun. However, in some cases, longer adjective phrases may be placed before the noun for emphasis or stylistic effect, although this is less common and should be done carefully to avoid confusion.

6. Can I use multiple adjectives of purpose in a single sentence?

Yes, you can use multiple adjectives of purpose in a single sentence, but ensure that each adjective clearly modifies the intended noun and that the sentence remains clear and easy to understand. Use proper punctuation and conjunctions to avoid ambiguity.

7. How do I avoid common mistakes when using adjectives of purpose?

To avoid common mistakes, double-check the word order, ensure that you use the correct prepositions with gerunds, and verify that you are using the appropriate form (gerund or infinitive) for the intended meaning. Review examples and practice exercises to reinforce your understanding.

8. Can adjectives of purpose be used with all types of nouns?

Adjectives of purpose can be used with both concrete and abstract nouns, but the context and meaning may vary. With concrete nouns, the adjective of purpose typically specifies the function or use of a physical object.

With abstract nouns, the adjective of purpose describes the intended outcome or goal of the concept.

Conclusion

Mastering adjectives of purpose is an essential step in enhancing your English grammar skills. By understanding their definition, structure, types, and usage rules, you can communicate more precisely and effectively.

Remember to pay attention to word order, preposition usage, and the appropriate choice between gerunds and infinitives. By avoiding common mistakes and practicing regularly, you can confidently use adjectives of purpose to add depth and clarity to your writing and speaking.

Continue to explore and practice using adjectives of purpose in various contexts. Pay attention to how native speakers use them in everyday conversations and written materials.

With consistent effort and attention to detail, you will become proficient in using adjectives of purpose to convey the intended function or use of nouns, enriching your overall command of the English language.