When you learn English, there are some elements that can sometimes feel tricky, but once you master them, they open the door to much clearer and more engaging communication. One of those elements is the combination of modal verbs and the passive voice.
In this article, we will dive into how modal verbs (like can, should, might, must, could, etc.) are used in the passive voice. We’ll explore the structures, the usage, and why this combination can be so important, especially in formal, scientific, and business writing.
What Are Modal Verbs?
Before we dive into the passive voice, it’s important to understand what modal verbs are. Modal verbs are auxiliary verbs that express necessity, possibility, permission, ability, or obligation. Some common modal verbs include:
- Can – ability, permission, possibility
- Could – past ability, possibility, polite requests
- May – permission, possibility
- Might – possibility, suggestion
- Must – necessity, obligation, assumption
- Should – recommendation, obligation
- Shall – offer, suggestion (mainly in British English)
- Will – future, willingness, requests
- Would – past habit, polite requests
some example sentences with modal verbs:
- Can – She can speak Spanish fluently.
- Should – You should visit the doctor.
- Must – He must finish his work by tomorrow.
- Might – She might come to the party later.
Modal verbs add nuance to statements, which is why they are essential in expressing different degrees of certainty or necessity.
What is the Passive Voice?
In active voice, the subject of the sentence performs the action, e.g., “John cleaned the room.” But in passive voice, the focus shifts to the object of the action rather than the doer. For example, “The room was cleaned by John.”
In passive voice, the object of the action becomes the subject of the sentence, and the verb changes to a form of “be” + past participle (e.g., was cleaned). The agent (the person doing the action) can be included or omitted, depending on whether it is necessary for the context.
Passive Voice Structure
- Subject + be + past participle (verb) + (by agent)
Let’s look at some examples:
- Active Voice: “She reads the book.”
- Passive Voice: “The book is read by her.”
The shift in focus from the subject (“She”) to the object (“The book”) is what makes the sentence passive. Passive voice is particularly useful when the doer of the action is unknown or irrelevant.
Modal Verbs in the Passive Voice
Now, let’s focus on how modal verbs can be used in the passive voice. The structure remains similar to passive voice in general, but with an added modal verb. The structure for using modal verbs in the passive voice is:
- Modal verb + be + past participle
For example:
- Active Voice: “You must complete the task.”
- Passive Voice: “The task must be completed.”
In the passive voice, the focus shifts from the subject (you) to the object (the task), and the modal verb “must” is still used to express necessity, but now the sentence emphasizes the action being done to the object.
Examples of Modal Verbs in the Passive Voice
| Active Voice | Passive Voice |
|---|---|
| She can solve the problem. | The problem can be solved by her. |
| They might visit the museum. | The museum might be visited by them. |
| He should write the report. | The report should be written by him. |
| You must finish the assignment. | The assignment must be finished by you. |
| They could improve the process. | The process could be improved by them. |
| We may attend the event. | The event may be attended by us. |
| She could ask for a raise. | A raise could be asked for by her. |
| He must complete the work. | The work must be completed by him. |
As you can see, we use the modal verb followed by “be” and the past participle of the main verb. This structure keeps the focus on the action being performed on the object, rather than the person performing it.
Modal Verbs in the Past Passive Voice
Just like with the present tense, modal verbs can also be used in the past passive voice. The past passive voice is used when the action was completed in the past, and the emphasis is still on the action or the result of the action, rather than who performed it.
The structure for the past passive voice with modal verbs is:
- Modal verb + have been + past participle
For example:
- Active Voice: “They could have completed the project.”
- Passive Voice: “The project could have been completed.”
This structure helps convey that the action might have occurred in the past, without focusing on the person who performed the action. Now, let’s look at how other modal verbs are used in the past passive voice.
Examples of Modal Verbs in the Past Passive Voice
| Active Voice | Passive Voice |
|---|---|
| They could have made the decision. | The decision could have been made. |
| She might have written the letter. | The letter might have been written by her. |
| He should have repaired the car. | The car should have been repaired by him. |
| We must have forgotten the meeting. | The meeting must have been forgotten by us. |
| They may have discussed the issue. | The issue may have been discussed by them. |
| I would have finished the work. | The work would have been finished by me. |
| You could have told me earlier. | I could have been told earlier by you. |
| She might have helped with the project. | The project might have been helped with by her. |
Understanding the Use of Past Passive Modal Verbs
In the past passive voice, we use modal verbs like could have, should have, and might have to reflect actions that could have occurred or should have been done in the past. This construction is especially useful when you want to express uncertainty or speculation about past events.
For example:
- Active: “You should have finished the work.”
- Passive: “The work should have been finished by you.”
The passive voice here shows that the work was expected to be completed by the subject, but we are focusing more on the work itself rather than who did it.
Why Use Modal Verbs in the Passive Voice?
You may wonder why modal verbs are used in the passive voice. There are several key reasons for using this construction in English, especially in professional, academic, or formal contexts.
1. Objectivity
Modal verbs in the passive voice help create a more objective tone. This is particularly useful when the focus is on the action or result, rather than on the individual performing the action. This is often seen in scientific writing or official reports where the action is more important than the person completing it.
For example:
- “The project must be completed by tomorrow” (Passive Voice)
- “You must complete the project by tomorrow” (Active Voice)
In the first sentence, the focus is on the project, not who is responsible for completing it. This makes the statement sound less personal and more formal.
2. Politeness
Using the passive voice with modal verbs can sound more polite and less direct. This is particularly helpful in formal communication when you want to avoid sounding too commanding or harsh.
For example, when giving instructions:
- Active Voice: “You need to finish the report by tomorrow.”
- Passive Voice: “The report needs to be finished by tomorrow.”
By using the passive construction, the tone is less direct and more impersonal, which may be preferred in many professional settings.
3. Emphasis on the Action or Result
Modal verbs in the passive voice emphasize the action or result rather than the person who performs the action. This is especially useful in formal contexts where the outcome of the action is more important than who is performing it.
For example:
- Active: “They must clean the office by Friday.”
- Passive: “The office must be cleaned by Friday.”
In the second example, the emphasis is on the cleaning of the office, not who is doing the cleaning.
4. Expressing Speculation about the Past
Using modal verbs in the passive voice is also a great way to express speculation or assumptions about past events. We often use must have been, could have been, or might have been to make educated guesses about what happened.
For example:
- Active Voice: “He must have made a mistake.”
- Passive Voice: “A mistake must have been made by him.”
This passive structure helps put the focus on the mistake, rather than who made it, and adds an element of uncertainty about the action itself.
Why Do We Use Modal Verbs in the Passive Voice?
Using modal verbs in the passive voice serves several important purposes, particularly in formal, academic, and professional communication. The passive voice with modal verbs helps to achieve a tone that is neutral, polite, and often more objective. Let’s explore the key reasons why we use this construction.
1. Objectivity and Neutrality
One of the main reasons to use modal verbs in the passive voice is to create a sense of objectivity and neutrality. When the focus is on the action or the result, rather than the person performing the action, the sentence becomes less personal and more focused on the event or outcome itself. This is particularly important in professional, scientific, and formal writing where the results or facts take precedence over the individual performing the action.
For example:
- Active Voice: “The researcher completed the study.”
- Passive Voice: “The study was completed by the researcher.”
In the second sentence, the emphasis is placed on the study being completed, not on the researcher, making the sentence sound more objective and formal.
2. Politeness and Tact
In many cases, using the passive voice with modal verbs can make statements sound politer and less direct. This is often used in situations where you want to avoid sounding too commanding, especially in professional settings. By using passive constructions, the tone of the sentence becomes more impersonal, which can soften requests, instructions, or criticism.
For example:
- Active Voice: “You must submit the report by tomorrow.”
- Passive Voice: “The report must be submitted by tomorrow.”
In the second example, the passive voice takes the focus off the person (you) and places it on the report, making the statement sound more like a neutral directive than a command.
3. Emphasis on the Action or Result
Another reason to use modal verbs in the passive voice is to emphasize the action or result rather than the subject performing it. This is especially useful when the result of the action is more important than the agent who carries it out. In formal writing, it’s common to emphasize the process or outcome, as it is often the most significant aspect of the communication.
For example:
- Active Voice: “They must complete the project by Friday.”
- Passive Voice: “The project must be completed by Friday.”
In the second sentence, the focus shifts from the doers (they) to the project itself, highlighting the need for completion rather than the person responsible.
4. To Avoid Blame or Focus on the Agent
Sometimes, passive constructions are used when the speaker wants to avoid assigning blame or putting too much focus on the doer of the action. The passive voice allows the speaker to take the focus off the individual and instead concentrate on the task, action, or result.
For example:
- Active Voice: “You should have sent the email earlier.”
- Passive Voice: “The email should have been sent earlier.”
By using the passive voice, the speaker avoids directly pointing to you (the person who should have acted), focusing on the email and the action of it being sent instead. This can help reduce potential tension in situations of blame or failure.
5. Expressing Speculation or Assumptions
Using modal verbs in the passive voice also helps to express speculation or assumptions about past or present actions. When discussing events or actions that might have happened, the passive voice allows for a more speculative tone, focusing on what might have occurred rather than who caused it.
For example:
- Active Voice: “He might have missed the meeting.”
- Passive Voice: “The meeting might have been missed by him.”
In the passive construction, the focus is placed on the meeting itself, and the possibility of it being missed, rather than the person who missed it.
6. In Scientific or Technical Writing
In scientific and technical writing, the use of passive voice with modal verbs is quite common. It helps maintain an impartial tone and focuses on the experiment, process, or result, rather than the person or researcher. This is particularly useful in research papers, where the process and findings are often considered more important than who conducted the research.
For example:
- Active Voice: “We have to conduct a series of tests.”
- Passive Voice: “A series of tests have to be conducted.”
Here, the action (conducting tests) is highlighted, which is more relevant to the research than the person conducting the tests.
Modal Verbs in the Passive Voice Exercise
Exercise 1: Change the Sentence from Active Voice to Passive Voice
Rewrite the following active voice sentences into passive voice. Pay attention to the modal verbs and ensure the correct passive voice structure is used.
- You have to finish your homework by 6 PM.
- They can solve the problem quickly.
- He might cancel the meeting.
- We must complete the project before Friday.
- You should clean the kitchen.
- She could finish the task earlier.
- The team must submit the report tomorrow.
- He might repair the car next week.
- You can use the computer to write the document.
- They should call the client before 3 PM.
Exercise 2: Choose the Correct Modal Structure
Fill in the blanks with the correct form of the modal verb in the passive voice. Use the structure: modal verb + be + past participle or modal verb + have been + past participle as appropriate.
- The document ______________ (should be / should have been) signed by the manager yesterday.
- The new rules ______________ (might be / might have been) introduced last week.
- This project ______________ (can be / could have been) finished by the end of the day.
- The instructions ______________ (must be / must have been) followed carefully during the procedure.
- The tickets ______________ (could be / could have been) purchased online earlier.
Exercise 3: Correct the Mistakes
Below are some sentences that incorrectly use modal verbs in the passive voice. Identify and correct the mistakes.
- The work should have been finished by you before the deadline.
- The task must be completed by yesterday.
- The car could be repaired by the mechanic last week.
- The invitation should be sent by tomorrow.
- The report must have been submitted before the meeting.
Exercise 4: Create Your Own Sentences
Using the modal verbs can, should, must, might, and could, create at least five sentences in the passive voice. Be sure to incorporate different tenses (present and past) and contexts (e.g., obligation, possibility, permission).
Conclusion On Modal Verbs in the Passive Voice
Understanding modal verbs in the passive voice is essential for expressing different levels of necessity, possibility, or obligation while focusing on the action or the result, rather than on the person performing the action. This construction is especially useful in formal, academic, and professional settings, where clarity, objectivity, and politeness are paramount.
Whether you’re writing a report, crafting an email, or making a presentation, knowing how to use modal verbs in the passive voice will help you convey your message more effectively and with the appropriate tone.
Now that you have a clearer understanding of modal verbs in the passive voice, don’t hesitate to practice incorporating them into your daily English use. With consistent practice, you’ll be able to master this structure and enhance the clarity and impact of your communication.