Prepositions of Agent: Mastering the “By” Phrase

Understanding prepositions of agent is crucial for constructing grammatically correct and clear sentences, especially in passive voice constructions. The preposition “by” is most commonly used to indicate the agent performing an action.

This article will explore the definition, usage, and common pitfalls associated with prepositions of agent, providing you with the knowledge and practice to confidently use them in your writing and speech. Whether you are a beginner or an advanced learner, this guide will help you refine your understanding and application of this important grammatical concept.

This guide will provide a detailed exploration of its usage, including various examples and practical exercises. By the end of this article, you’ll have a solid understanding of how to use prepositions of agent effectively and avoid common mistakes.

Let’s dive in!

Table of Contents

1. Introduction
2. Definition of Preposition of Agent
3. Classification
4. Function
5. Context
6. Structural Breakdown
7. Types and Categories
8. Examples of Prepositions of Agent
9. Examples using “By”
10. Examples using “With”
11. Examples using “Through”
12. Examples using “From”
13. Usage Rules
14. Active vs. Passive Voice
15. Exceptions
16. Special Cases
17. Common Mistakes
18. Practice Exercises
19. Exercise 1: Identifying the Agent
20. Exercise 2: Rewriting Active to Passive Voice
21. Exercise 3: Error Correction
22. Advanced Topics
23. Omitting the Agent
24. Prepositions of Agent in Complex Sentences
25. FAQ
26. Conclusion

Definition of Preposition of Agent

A preposition of agent is a preposition that indicates the person or thing that performs an action, especially in passive voice sentences. It identifies who or what is responsible for the action described by the verb. The most common preposition of agent is “by,” but others like “with,” “through,” and “from” can also function as prepositions of agent depending on the context.

Classification

Prepositions of agent fall under the broader category of prepositions, which are words that show the relationship between a noun or pronoun and other words in a sentence. More specifically, they are a subset of prepositions that denote agency or cause.

Unlike prepositions of location or time, prepositions of agent specify the entity that carries out the action.

Function

The primary function of a preposition of agent is to identify the actor in a passive voice sentence. In active voice, the subject performs the action.

However, in passive voice, the subject receives the action, and the agent (the one performing the action) is introduced by a preposition. This is especially useful when the actor is important to mention, or when the focus is on the action itself rather than the actor.

Context

The context in which a preposition is used is crucial in determining whether it functions as a preposition of agent. For instance, “with” can indicate the instrument used to perform an action, while “by” usually indicates the person or entity.

The meaning of the sentence and the relationship between the words determine the function of the preposition.

Structural Breakdown

The structure involving a preposition of agent typically follows this pattern in passive voice sentences:

Subject + Verb (to be) + Past Participle + Preposition of Agent + Agent

For example:

• The book was written by Jane Austen.
• The door was opened by the wind.
• The cake was decorated with frosting.

In these examples, “by Jane Austen” and “by the wind”, and “with frosting” identify the agent responsible for the action described by the verb (written, opened, decorated).

Types and Categories

While “by” is the most common, other prepositions can function as prepositions of agent. Understanding these variations is key to mastering this grammatical concept.

• By: Indicates the direct agent performing the action.
• With: Often indicates the instrument or tool used to perform the action.
• Through: Indicates the means or channel through which the action is performed.
• From: Indicates the source from which something originates.

Examples of Prepositions of Agent

Let’s explore various examples of prepositions of agent in different contexts. These examples will help illustrate how each preposition functions and how to identify the agent in a sentence.

Examples using “By”

The preposition “by” is the most common preposition of agent, indicating who or what performed the action. It is primarily used in passive voice sentences to identify the actor.

The following table provides examples of sentences using “by” as a preposition of agent.

Sentence
The novel was written by Charles Dickens.
The painting was created by Leonardo da Vinci.
The song was sung by Adele.
The house was built by local contractors.
The mistake was made by accident.
The car was driven by my brother.
The food was cooked by my mother.
The report was written by the committee.
The decision was made by the board of directors.
The city was destroyed by the earthquake.
The letter was delivered by the postman.
The play was directed by Steven Spielberg.
The rule was enforced by the police.
The mystery was solved by the detective.
The problem was identified by the analyst.
The email was sent by John.
The event was organized by the students.
The project was completed by the team.
The article was edited by the editor.
The website was designed by a freelancer.
The experiment was conducted by the scientists.
The data was analyzed by the software.
The error was corrected by the programmer.
The presentation was given by the CEO.
The meeting was chaired by the manager.
The contract was signed by both parties.
The law was passed by the government.
The bill was paid by my father.

Examples using “With”

The preposition “with” often indicates the instrument or tool used to perform an action. In these cases, “with” acts as a preposition of agent, specifying the means by which the action is carried out.

The following table provides examples of sentences using “with” as a preposition of agent.

Sentence
The door was opened with a key.
The painting was created with oil paints.
The cake was decorated with frosting.
The letter was written with a pen.
The table was cleaned with a cloth.
The hole was dug with a shovel.
The meat was cut with a knife.
The wound was treated with antiseptic.
The car was fixed with new parts.
The bread was sliced with a bread knife.
The garden was watered with a hose.
The floor was swept with a broom.
The wall was painted with a brush.
The grass was cut with a lawnmower.
The wood was carved with a chisel.
The salad was tossed with dressing.
The coffee was stirred with a spoon.
The soup was seasoned with salt and pepper.
The drawing was shaded with a pencil.
The sculpture was molded with clay.
The message was encrypted with a code.
The problem was solved with a computer.
The document was printed with a printer.
The task was completed with great effort.
The project was finished with dedication.
The presentation was enhanced with visuals.
The report was improved with feedback.
The system was secured with a password.

Examples using “Through”

The preposition “through” indicates the means or channel through which the action is performed. This usage is less common but still valid in certain contexts.

The following table provides examples of sentences using “through” as a preposition of agent.

Sentence
The information was disseminated through the media.
The message was conveyed through an interpreter.
The deal was negotiated through a lawyer.
The package was sent through the postal service.
The complaint was filed through the online portal.
The funds were transferred through the bank.
The news was spread through word of mouth.
The application was submitted through the website.
The order was placed through a phone call.
The donation was made through a charity organization.
The project was managed through a project manager.
The event was promoted through social media.
The sale was finalized through an auction.
The agreement was reached through negotiations.
The problem was resolved through mediation.
The data was collected through a survey.
The feedback was gathered through interviews.
The research was conducted through experiments.
The course was delivered through online platform.
The training was provided through workshops.
The support was offered through helpline.
The progress was monitored through regular updates.
The system was accessed through login credentials.
The access was granted through authorization process.
The approval was obtained through proper channels.
The permission was granted through official request.
The task was accomplished through team efforts.

Examples using “From”

The preposition “from” indicates the source from which something originates. Although less typical, it can function as a preposition of agent when specifying the source or originator of an action or information.

The following table provides examples of sentences using “from” as a preposition of agent.

Sentence
The quote was taken from Shakespeare.
The story was adapted from a novel.
The recipe was learned from my grandmother.
The idea was inspired from a dream.
The advice was received from a mentor.
The information was obtained from a reliable source.
The product was purchased from a local store.
The funds were raised from donations.
The support was received from family and friends.
The inspiration was drawn from nature.
The knowledge was gained from experience.
The skill was developed from practice.
The habit was acquired from childhood.
The custom was inherited from ancestors.
The tradition was passed down from generations.
The law was derived from ethical principles.
The theory was developed from observations.
The model was created from data analysis.
The innovation was born from necessity.
The change was initiated from the top.
The order was issued from the headquarters.
The command was given from the captain.
The announcement was made from the stage.
The message was delivered from a messenger.
The warning was issued from the authorities.
The concern was raised from the community.
The question was asked from the audience.

Usage Rules

Understanding the rules governing the use of prepositions of agent is essential for correct grammar. These rules encompass the relationship between active and passive voice, common exceptions, and special cases.

Active vs. Passive Voice

Prepositions of agent are primarily used in passive voice sentences. In active voice, the subject performs the action, while in passive voice, the subject receives the action.

The agent is then introduced using a preposition.

• Active: Shakespeare wrote the play.
• Passive: The play was written by Shakespeare.

In the active sentence, Shakespeare is the subject and performs the action. In the passive sentence, the play is the subject, and Shakespeare is the agent, introduced by “by.”

Exceptions

There are some exceptions where the preposition of agent might be omitted, especially when the agent is unknown, unimportant, or obvious from the context.

• The window was broken. (Agent is unknown)
• Mistakes were made. (Agent is unimportant in this context)

In these cases, including the agent would not add significant meaning to the sentence.

Special Cases

In some cases, the choice of preposition depends on the type of action and the relationship between the subject and the agent. For example, “with” is used to indicate the instrument, while “by” is used to indicate the performer of the action.

• The door was opened by the security guard. (Performer)
• The door was opened with a key. (Instrument)

Here, “by” indicates who opened the door, while “with” indicates what was used to open the door.

Common Mistakes

Several common mistakes can occur when using prepositions of agent. Recognizing and correcting these errors is crucial for improving your grammar.

1. Incorrect Preposition: Using the wrong preposition to indicate the agent.

• Incorrect: The letter was written with John.
• Correct: The letter was written by John.

2. Missing Preposition: Omitting the preposition when it is necessary to identify the agent.

• Incorrect: The cake was baked Mary.
• Correct: The cake was baked by Mary.

3. Active Voice Confusion: Using passive voice incorrectly, leading to awkward sentences.

• Incorrect: The book was read by me.
• Correct: I read the book.

4. Unnecessary Passive Voice: Overusing passive voice when active voice would be clearer and more direct.

• Incorrect: The report was prepared by the team.
• Correct: The team prepared the report.

Practice Exercises

Practice is key to mastering prepositions of agent. These exercises will help you reinforce your understanding and improve your ability to use them correctly.

Exercise 1: Identifying the Agent

Identify the agent in each of the following passive voice sentences.

Question	Answer
1. The picture was painted by Van Gogh.	Van Gogh
2. The email was sent by Sarah.	Sarah
3. The car was repaired with new parts.	New parts
4. The message was conveyed through an interpreter.	An interpreter
5. The cake was decorated with frosting.	Frosting
6. The house was built by the construction company.	The construction company
7. The article was written by a journalist.	A journalist
8. The song was sung by the choir.	The choir
9. The door was opened with a key.	A key
10. The book was translated by a professor.	A professor

Exercise 2: Rewriting Active to Passive Voice

Rewrite the following active voice sentences into passive voice sentences, using a preposition of agent.

Question	Answer
1. John wrote the letter.	The letter was written by John.
2. The chef cooked the meal.	The meal was cooked by the chef.
3. The students organized the event.	The event was organized by the students.
4. The wind opened the window.	The window was opened by the wind.
5. The artist created the sculpture.	The sculpture was created by the artist.
6. The mechanic fixed the car.	The car was fixed by the mechanic.
7. The author wrote the book.	The book was written by the author.
8. The team completed the project.	The project was completed by the team.
9. The director filmed the movie.	The movie was filmed by the director.
10. The teacher graded the papers.	The papers were graded by the teacher.

Exercise 3: Error Correction

Identify and correct the errors in the following sentences related to prepositions of agent.

Question	Answer
1. The cake was baked with my mom.	The cake was baked by my mom.
2. The report was written the committee.	The report was written by the committee.
3. The door was opened by a hammer.	The door was opened with a hammer.
4. The information was spread from the internet.	The information was spread through the internet.
5. The song was sung with Adele.	The song was sung by Adele.
6. The house was built with local contractors.	The house was built by local contractors.
7. The letter was delivered the postman.	The letter was delivered by the postman.
8. The play was directed from Steven Spielberg.	The play was directed by Steven Spielberg.
9. The rule was enforced with the police.	The rule was enforced by the police.
10. The mystery was solved with the detective.	The mystery was solved by the detective.

Advanced Topics

For advanced learners, understanding more complex aspects of prepositions of agent can further refine their grammar skills. These topics include omitting the agent and using prepositions of agent in complex sentences.

Omitting the Agent

In certain situations, the agent can be omitted from a passive voice sentence without affecting its meaning or clarity. This is often done when the agent is unknown, unimportant, or obvious from the context.

• The window was broken. (Agent is unknown)
• The decision was made. (Agent is unimportant)
• The thief was arrested. (Agent is obvious – by the police)

Omitting the agent can make sentences more concise and focus attention on the action rather than the actor.

Prepositions of Agent in Complex Sentences

Prepositions of agent can also be used in complex sentences, where multiple clauses are combined. Understanding how to use them correctly in these constructions is crucial for advanced writing.

• The book, which was written by a famous author, became a bestseller.
• The project, which was completed by the team, received high praise.
• The experiment, which was conducted by the scientists, yielded significant results.

In these examples, the preposition of agent is used within a relative clause to provide additional information about the subject.

FAQ

Here are some frequently asked questions about prepositions of agent.

1. What is a preposition of agent?

   A preposition of agent is a preposition that indicates the person or thing that performs an action, especially in passive voice sentences. It identifies who or what is responsible for the action described by the verb. The most common preposition of agent is “by.”

2. When should I use “by” as a preposition of agent?

   Use “by” when you want to specify the person or entity that performed the action in a passive voice sentence. For example, “The book was written by Jane Austen.”

3. Can other prepositions function as prepositions of agent?

   Yes, prepositions like “with,” “through,” and “from” can also function as prepositions of agent depending on the context. “With” often indicates the instrument used to perform an action, while “through” indicates the means or channel.

4. How do I identify the agent in a passive voice sentence?

   Look for the preposition that introduces the person or thing responsible for the action. Typically, this is “by,” but it could also be “with,” “through,” or “from.”

5. Why is it important to use the correct preposition of agent?

   Using the correct preposition of agent ensures clarity and accuracy in your writing. It helps avoid confusion about who or what performed the action.

6. When can I omit the preposition of agent in a passive voice sentence?

   You can omit the preposition of agent when the agent is unknown, unimportant, or obvious from the context. For example, “The window was broken” (agent is unknown).

7. What is the difference between active and passive voice?

   In active voice, the subject performs the action (e.g., “John wrote the letter”). In passive voice, the subject receives the action, and the agent is introduced by a preposition (e.g., “The letter was written by John”).

8. How can I improve my use of prepositions of agent?

   Practice identifying and using prepositions of agent in various contexts. Pay attention to the relationship between the subject and the agent, and review examples to reinforce your understanding.

Conclusion

Mastering prepositions of agent is essential for constructing clear and grammatically correct sentences, especially in passive voice. By understanding the definition, usage rules, and common mistakes associated with these prepositions, you can significantly improve your writing and communication skills.

Remember to practice regularly and pay attention to the context in which these prepositions are used.

This comprehensive guide has provided you with the knowledge and tools to confidently use prepositions of agent. Continue to practice and refine your understanding, and you will become proficient in using these important grammatical elements.

With consistent effort, you’ll find your writing becomes more precise and effective, allowing you to communicate your ideas with greater clarity.