Mastering the Past Tense of ‘Monitor’: Forms, Usage & Examples

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The English verb “monitor” is a highly versatile word used across many fields, including technology, healthcare, education, and business. It means to observe, track, supervise, or check something carefully over a period of time. Using the correct past tense forms of “monitor” is crucial for conveying clear, precise meaning in academic writing, professional reports, and everyday conversations.

Understanding verb tenses helps learners accurately describe past events and sequences. For ESL students, professionals, and writers, mastering the past tense of “monitor” ensures effective communication, whether recounting a completed task, writing research findings, or narrating events.

This comprehensive guide will cover everything you need to know: definitions, grammatical structure, spelling and pronunciation, tense variations, rich examples, usage rules, common mistakes, practice exercises with answers, advanced nuances, and a detailed FAQ. By the end, you’ll confidently use “monitored” and its related forms across various contexts.

Let’s dive in!

Table of Contents

3. Definition Section

3.1. What Does “Monitor” Mean?

As a verb, monitor means to observe, watch, supervise, or check something carefully over a period of time, often to gather information or ensure proper functioning.

As a noun, it refers to a device or person who performs monitoring. However, this article focuses on the verb form.

Present tense examples:

  • The nurse monitors the patient’s vital signs every hour.
  • Scientists monitor the volcano for signs of activity.
  • The software monitors network traffic continuously.
  • Teachers monitor student progress throughout the semester.
  • Environmentalists monitor air quality in the city.

3.2. Grammatical Classification of “Monitor”

“Monitor” is a regular verb.

Regular verbs form their simple past and past participle by adding -ed to the base form.

Comparison table: regular vs. irregular verbs

Verb Base Form Simple Past Past Participle Type
monitor monitor monitored monitored Regular
go go went gone Irregular
write write wrote written Irregular
play play played played Regular
study study studied studied Regular

3.3. The Role of Past Tense in English Verbs

The simple past tense describes actions or events that were completed at a definite time in the past.

For the verb “monitor,” the simple past is used when:

  • Reporting past activities: The technician monitored the equipment yesterday.
  • Describing historical events: Scientists monitored the volcano during the 1980 eruption.
  • Summarizing completed supervision: She monitored the exam effectively.
  • Writing about previous studies: This research monitored 200 participants over five years.

4. Structural Breakdown

4.1. Forming the Simple Past of “Monitor”

Base form: monitor

Past tense: monitored

Past participle: monitored

Rule: For regular verbs, add -ed to the base form:

monitor + -ed → monitored

Conjugation Table:

Base Form Simple Past Past Participle
monitor monitored monitored

4.2. Spelling Considerations

For “monitor,” the spelling is straightforward:

  • It does not end with -e, so simply add -ed.
  • It does not end with -y, so no change to -ied.
  • No need to double the consonant.

Examples of spelling changes with other verbs:

  • study → studied (change -y to -ied)
  • stop → stopped (double the consonant + ed)
  • live → lived (just add -d after final -e)

Spelling rules summary:

Base Verb Rule Past Form
monitor Add -ed monitored
study Change -y to -ied studied
stop Double consonant + ed stopped
live Add -d lived
play Add -ed played

4.3. Pronunciation of “Monitored”

The pronunciation of the past tense -ed ending varies:

  • /t/ after voiceless sounds (e.g., watched)
  • /d/ after voiced sounds (e.g., called)
  • /ɪd/ after t or d sounds (e.g., wanted, needed)

“Monitored” ends with a voiced sound, so -ed is pronounced as /d/.

IPA: /ˈmɒnɪtərd/

Pronunciation table:

Sound Before -ed Example Verb Past Form Pronunciation of -ed
Voiceless consonant (/p/, /k/, /s/) watch watched /t/
Voiced consonant (/n/, /l/, /r/) monitor monitored /d/
Base ends with /t/ or /d/ need needed /ɪd/
Base ends with /t/ want wanted /ɪd/

4.4. Past Tense Structures with “Monitor”

Affirmative:

Subject + monitored + rest of sentence

The team monitored the experiment.

Negative:

Subject + did not + base form monitor + rest

The team did not monitor the experiment.

Interrogative:

Did + subject + base form monitor + rest?

Did the team monitor the experiment?

Short answers:

  • Yes, they did.
  • No, they didn’t.

Summary Table:

Sentence Type Structure Example
Affirmative Subject + monitored + object The team monitored the experiment.
Negative Subject + did not + monitor + object The team did not monitor the experiment.
Interrogative Did + subject + monitor + object? Did the team monitor the experiment?
Short Answer (Yes) Yes, subject + did. Yes, they did.
Short Answer (No) No, subject + didn’t. No, they didn’t.

5. Types or Categories

5.1. Simple Past Tense (Main focus)

Describes a completed action in the past.

She monitored the patient yesterday.

5.2. Past Continuous with “Monitor”

Expresses an ongoing action in the past, often interrupted by another event.

Formed with was/were + monitoring.

They were monitoring the system all night.

Comparison table:

Simple Past Past Continuous
She monitored the patient yesterday. She was monitoring the patient when the alarm sounded.
We monitored the server during the update. We were monitoring the server throughout the update.

5.3. Past Perfect with “Monitor”

Indicates an action completed before another past event.

Formed with had + past participle.

By noon, the scientists had monitored all samples.

Use cases:

  • Showing sequence of past actions
  • Emphasizing earlier completion

5.4. Passive Voice Past Forms

Used to focus on the receiver of the action.

Simple past passive:

The patient was monitored carefully.

Past perfect passive:

The results had been monitored by the team.

Passive construction:

  • Simple past: was/were + past participle
  • Past perfect: had been + past participle

6. Examples Section

6.1. Basic Affirmative Sentences

  • The doctor monitored my condition.
  • Researchers monitored the wildlife.
  • The company monitored employee attendance.
  • Experts monitored air pollution levels.
  • The teacher monitored the exam closely.
  • Security staff monitored the entrance.
  • Volunteers monitored the cleanup efforts.
  • The police monitored the protest.
  • The app monitored my sleep patterns.
  • They monitored the satellite signals.

6.2. Negative Sentences

  • They did not monitor the device.
  • The security team didn’t monitor the cameras properly.
  • The nurse didn’t monitor the patient last night.
  • We did not monitor the temperature changes.
  • The system didn’t monitor real-time data.
  • He didn’t monitor his expenses last month.
  • The lab didn’t monitor humidity levels.
  • They didn’t monitor the children during recess.
  • I did not monitor my calorie intake.
  • The agency didn’t monitor the border that day.

6.3. Interrogative Sentences

  • Did you monitor the changes?
  • Did the analyst monitor the market trends?
  • Did the doctor monitor your recovery?
  • Did the team monitor the new system?
  • Did they monitor the wildlife reserve?
  • Did the teacher monitor the students’ progress?
  • Did the police monitor the suspect?
  • Did you monitor the network yesterday?
  • Did he monitor the security footage?
  • Did we monitor the patient’s response?

6.4. Past Continuous Examples

  • She was monitoring the patient overnight.
  • We were monitoring network traffic all day.
  • The researchers were monitoring the volcano during the eruption.
  • Security was monitoring the premises continuously.
  • They were monitoring the experiment when the power went out.
  • I was monitoring the system updates last night.
  • They were monitoring the weather conditions closely.
  • He was monitoring the data feeds for errors.
  • The staff were monitoring customer feedback.
  • We were monitoring the process step by step.

6.5. Past Perfect Examples

  • They had already monitored the situation before the crisis escalated.
  • By 5 PM, the engineers had monitored every system.
  • The scientists had monitored the experiment for weeks before publishing.
  • He had monitored the patient before the shift change.
  • We had monitored the sales data prior to the meeting.
  • They had monitored air quality before the festival began.
  • The team had monitored the software for bugs before launch.
  • She had monitored the students’ progress before exams.
  • The authorities had monitored the suspect’s movements.
  • I had monitored the test results before reporting.

6.6. Passive Voice Examples

  • The experiment was monitored by experts.
  • All activities had been monitored closely.
  • The server was monitored throughout the night.
  • The patient was monitored every hour.
  • The area was monitored using drones.
  • The event was monitored by security officials.
  • The data was monitored and recorded carefully.
  • The meeting was monitored by a supervisor.
  • Results had been monitored by the research team.
  • Communication was monitored for quality control.

6.7. Examples Table 1: Affirmative, Negative, Question Forms

Type Example
Affirmative The technicians monitored the machines.
Negative The technicians did not monitor the machines.
Question Did the technicians monitor the machines?

6.8. Examples Table 2: Tense Variations

Tense Example
Simple Past She monitored the patient yesterday.
Past Continuous She was monitoring the patient when the alarm sounded.
Past Perfect She had monitored the patient before the shift change.

6.9. Examples Table 3: Active vs. Passive Voice

Voice Example
Active The security team monitored the entrance.
Passive The entrance was monitored by the security team.

6.10. Examples Table 4: Formal vs. Informal Contexts

Context Example
Formal (academic) The study monitored 300 participants over two years.
Formal (business) The manager monitored project progress weekly.
Informal (conversation) Yeah, I monitored the situation last night.
Informal (casual) We didn’t really monitor what he was doing.

6.11. Examples Table 5: Academic, Workplace, and Everyday Usage

Setting Example
Academic The researchers monitored plant growth over six months.
Workplace IT staff monitored the network during the upgrade.
Everyday I monitored my bank account last week.
Medical The nurse monitored the patient’s vital signs.
Technical The app monitored CPU usage constantly.

7. Usage Rules

7.1. When to Use Simple Past “Monitored”

Use the simple past when:

  • The action is completed in the past
  • The time of the action is specified or understood

Common time markers: yesterday, last week, in 2020, two days ago

They monitored the process last month.

7.2. Contextual Use Cases

  • Scientific reporting: The study monitored 500 patients.
  • Medical observations: Nurses monitored the patient’s recovery.
  • Project management: The manager monitored team performance.
  • Security and surveillance: Authorities monitored the border crossing.

7.3. Sequence of Past Actions

Use past perfect for the earlier action and simple past for the later action.

The scientists had monitored the samples before publishing their findings.

7.4. Common Time Expressions

  • yesterday
  • last week/month/year
  • two days ago
  • earlier
  • in 2020
  • in the past
  • this morning (if referring to a past, completed time)

Time expressions table:

Time Expression Example Sentence
yesterday They monitored the system yesterday.
last week She monitored the experiment last week.
two days ago We monitored the equipment two days ago.
in 2020 Scientists monitored the volcano in 2020.
earlier The technician monitored the process earlier.

7.5. Exceptions & Special Cases

Because “monitor” is regular, there are few exceptions.

Rarely, informal speech might omit auxiliary verbs or use non-standard forms, but these are incorrect in standard English.

7.6. Register and Formality

In formal writing (academic or professional), passive forms are often preferred:

The patient was monitored throughout the procedure.

In everyday conversation, active voice is more common:

We monitored the patient all night.

8. Common Mistakes

8.1. Incorrect Past Tense Formation

  • Wrong: Monitorred
  • Correct: Monitored
  • Wrong: I monitor the process yesterday.
  • Correct: I monitored the process yesterday.

8.2. Overusing Continuous or Perfect Forms

Sometimes, learners use complex forms unnecessarily:

  • Overly complex: They were monitoring the machine yesterday.
  • Simpler (preferred if action is complete): They monitored the machine yesterday.

8.3. Confusing Active and Passive

  • Incorrect: The patient monitored carefully.
  • Correct: The patient was monitored carefully.

8.4. Misplacing “Did” in Negatives and Questions

  • Incorrect: Did monitored the system?
  • Correct: Did you monitor the system?
  • Incorrect: They did monitored the data.
  • Correct: They did monitor the data.

8.5. Incorrect Time Marker Usage

  • Incorrect: Yesterday, I monitor the situation.
  • Correct: Yesterday, I monitored the situation.

8.6. Table of Common Errors and Corrections

Error Correction
She monitor the patient yesterday. She monitored the patient yesterday.
They did monitored the device. They did monitor the device.
The patient monitored carefully. The patient was monitored carefully.
Did monitored the changes? Did you monitor the changes?
Monitorred Monitored

8.7. Practice: Identify and correct the errors

  1. She monitor the data last week. → She monitored the data last week.
  2. The team didn’t monitored the system. → The team didn’t monitor the system.
  3. Did you monitored the patient? → Did you monitor the patient?
  4. The experiment was monitor by experts. → The experiment was monitored by experts.
  5. They was monitoring the network yesterday. → They were monitoring the network yesterday.

9. Practice Exercises

9.1. Fill-in-the-Blank

  1. Yesterday, the team _______ (monitor) the network.
  2. The scientists _______ (monitor) the volcano in 2019.
  3. She _______ (not monitor) her heart rate last night.
  4. _______ (you / monitor) the new server?
  5. By noon, they _______ (monitor) all samples.

9.2. Correct the Mistake

  1. She monitor the progress last week.
  2. They did monitored the traffic.
  3. Did you monitored the process?
  4. The patient monitor carefully.
  5. Yesterday, we monitor the equipment.

9.3. Choose the Correct Form

  1. The doctor (monitor / monitored) the patient yesterday.
  2. They (was monitoring / were monitoring) the system all night.
  3. We (had monitored / have monitored) the project before the deadline.
  4. Did you (monitor / monitored) the changes?
  5. The data (was monitored / were monitored) by experts.

9.4. Identify the Tense

  1. We monitored the process carefully. → _______
  2. They were monitoring the server when it crashed. → _______
  3. She had monitored the patient before the shift ended. → _______
  4. The system was monitored overnight. → _______
  5. I was monitoring the updates yesterday. → _______

9.5. Sentence Construction

  • Make an affirmative sentence in simple past using “monitored”.
  • Make a negative past sentence with “monitor”.
  • Make a question using “Did” and “monitor”.
  • Make a passive sentence in simple past with “monitor”.
  • Make a past perfect sentence with “monitor”.

9.6. Transformation Exercises

  • Change to passive: The scientists monitored the experiment.
  • Change to active: The experiment was monitored by the scientists.
  • Change to past continuous: They monitored the volcano.
  • Change to past perfect: They monitored the volcano.
  • Change to negative: They monitored the volcano.

9.7. Answer Key

9.1. Fill-in-the-Blank

  1. monitored
  2. monitored
  3. did not monitor
  4. Did you monitor
  5. had monitored

9.2. Correct the Mistake

  1. She monitored the progress last week.
  2. They did not monitor the traffic.
  3. Did you monitor the process?
  4. The patient was monitored carefully.
  5. Yesterday, we monitored the equipment.

9.3. Choose the Correct Form

  1. monitored
  2. were monitoring
  3. had monitored
  4. monitor
  5. was monitored

9.4. Identify the Tense

  1. Simple past
  2. Past continuous
  3. Past perfect
  4. Simple past passive
  5. Past continuous

9.5. Sentence Construction

  • The engineer monitored the new system.
  • They did not monitor the weather data.
  • Did you monitor the cameras yesterday?
  • The patient was monitored overnight.
  • They had monitored the results before the meeting.

9.6. Transformation Exercises

  • The experiment was monitored by the scientists.
  • The scientists monitored the experiment.
  • They were monitoring the volcano.
  • They had monitored the volcano.
  • They did not monitor the volcano.

10. Advanced Topics

10.1. Reported Speech with “Monitored”

When reporting what someone said, the tense often shifts back:

Direct: She said, “We monitored the trial.”

Reported: She said they had monitored the trial.

10.2. Subjunctive and Hypotheticals

Hypothetical conditionals:

If they had monitored the data, the error might have been avoided.

10.3. Collocations and Phrasal Verbs

Common collocations:

  • monitor closely
  • monitor continuously
  • monitor remotely
  • monitor carefully
  • monitor progress
  • monitor performance

10.4. Past Tense in Academic and Technical Writing

Passive and perfect forms create a more formal tone:

The patients were monitored for adverse effects.

All samples had been monitored prior to analysis.

10.5. Nuances of Emphasis and Tone

  • Simple past: straightforward completion of an action
  • Past continuous: emphasizes duration or interruption
  • Past perfect: emphasizes prior completion before another event

11. FAQ Section

  1. What is the simple past tense of “monitor”?
    It is monitored.
  2. Is “monitored” a regular or irregular past tense form?
    It is a regular verb, formed by adding -ed.
  3. How do I pronounce “monitored”?
    /ˈmɒnɪtərd/, with the -ed pronounced as /d/.
  4. Can “monitor” be used in the past continuous tense?
    Yes, as was/were monitoring (e.g., They were monitoring the system).
  5. How do I use “monitored” in passive voice?
    Use was/were monitored (e.g., The patient was monitored).
  6. What are common mistakes with “monitored”?
    Misspelling (monitorred), incorrect forms (did monitored), confusing active/passive, or wrong time markers.
  7. Are there spelling changes when making “monitor” past tense?
    No, just add -ed: monitored.
  8. How do I form negative past tense sentences with “monitor”?
    Subject + did not + monitor (base verb), e.g., They did not monitor the system.
  9. What is the difference between “was monitoring” and “monitored”?
    “Monitored” = completed past action; “was monitoring” = ongoing past action.
  10. Can “monitored” be used in reported speech?
    Yes, often as past perfect: She said they had monitored the project.
  11. Is “monitored” used differently in formal writing?
    Often passive forms are preferred for objectivity: The data were monitored.
  12. What time expressions go with the past tense of “monitor”?
    Yesterday, last week, in 2020, two days ago, earlier, etc.

12. Conclusion

In summary, “monitor” is a regular verb whose past tense and past participle form is “monitored”. It is widely used to describe observation and supervision activities across contexts.

Mastering its past forms helps you clearly express completed actions, sequences, and ongoing processes in the past. Remember key rules for forming negatives, questions, and passive voice.

Pay attention to common mistakes and practice often using the examples and exercises provided.

Developing confidence with “monitored” strengthens your overall English proficiency, especially in academic and professional communication. Keep revisiting this guide as a detailed reference and continue refining your command of English verb tenses.

Happy learning!

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