Lesson 9
Verb Forms: Do, Modals, Perfect, Continuous and Passive
This lesson groups five rules that students commonly confuse because they look similar on the surface. Look at the helper verb first; it determines the form that follows. Work through the examples slowly once; speed comes after the pattern is clear.
What you will learn
- Understand and apply: After do/does/did, use the base form.
- Understand and apply: After a modal, use the base form.
- Understand and apply: Perfect tenses use a past participle.
- Understand and apply: Continuous tenses use be + present participle.
- Understand and apply: Passive voice uses be + past participle.
For every rule: spot the trigger → identify the grammatical relationship → apply the form → check meaning.
Before you start
Try the warm-up without checking the rule. The purpose is to expose the instinct you currently use, not to score marks.
Which sentence follows the target grammar pattern?
A. She does not know the answer.
B. She does not knows the answer.
Answer: A. When do, does or did carries tense, the following main verb stays in the base form.
Rule 1 · G041
After do/does/did, use the base form
When do, does or did carries tense, the following main verb stays in the base form.
Correct example
She does not know the answer.
Incorrect example
She does not knows the answer.
Interpretation
When do, does or did carries tense, the following main verb stays in the base form. In a test, do not memorise this as an isolated sentence. Look at the helper verb first; it determines the form that follows. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.
Why it matters
Auxiliaries sharply restrict the form that can follow, making these high-confidence marks once the pattern is recognised.
Common exam trap
Adding tense twice: once on the auxiliary and again on the main verb.
How to spot it
Look for the fixed trigger in the rule title before deciding whether the sentence merely sounds natural.
3-step solving method
- Circle the auxiliary or trigger.
- Write the form it requires (base/-ing/past participle).
- Check that tense is not marked twice.
Why the incorrect example fails
The target structure requires this rule: When do, does or did carries tense, the following main verb stays in the base form. In the incorrect version, the repair is to replace “knows” with “know”. That is the exact edit a student should be able to justify in an error-spotting question.
Nuance and memory hook
Do not identify a form only by its spelling; the same -ed or -ing form can perform different grammatical jobs.
When do, does or did carries tense, the following main verb stays in the base form.
Quick check
Without relying on what 'sounds right', explain which part of this sentence violates the rule: “She does not knows the answer.”
Reveal quick check answer
Apply After do/does/did, use the base form: When do, does or did carries tense, the following main verb stays in the base form.
Practice questions
Apply the rule in context
Which sentence is the better choice in standard exam-oriented English?
Explain the error rather than guessing by sound
Why is this sentence problematic in the target rule? “She does not knows the answer.”
Rule 2 · G042
After a modal, use the base form
Can, could, may, might, must, shall, should, will and would are normally followed by the bare infinitive.
Correct example
You should revise the error log.
Incorrect example
You should revises the error log.
Interpretation
Can, could, may, might, must, shall, should, will and would are normally followed by the bare infinitive. In a test, do not memorise this as an isolated sentence. Look at the helper verb first; it determines the form that follows. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.
Why it matters
Auxiliaries sharply restrict the form that can follow, making these high-confidence marks once the pattern is recognised.
Common exam trap
Adding tense twice: once on the auxiliary and again on the main verb.
How to spot it
Look for the fixed trigger in the rule title before deciding whether the sentence merely sounds natural.
3-step solving method
- Circle the auxiliary or trigger.
- Write the form it requires (base/-ing/past participle).
- Check that tense is not marked twice.
Why the incorrect example fails
The target structure requires this rule: Can, could, may, might, must, shall, should, will and would are normally followed by the bare infinitive. In the incorrect version, the repair is to replace “revises” with “revise”. That is the exact edit a student should be able to justify in an error-spotting question.
Nuance and memory hook
Do not identify a form only by its spelling; the same -ed or -ing form can perform different grammatical jobs.
Modal + base verb.
Quick check
Without relying on what 'sounds right', explain which part of this sentence violates the rule: “You should revises the error log.”
Reveal quick check answer
Apply After a modal, use the base form: Can, could, may, might, must, shall, should, will and would are normally followed by the bare infinitive.
Practice questions
Apply the rule in context
Which sentence is the better choice in standard exam-oriented English?
Explain the error rather than guessing by sound
Why is this sentence problematic in the target rule? “You should revises the error log.”
Rule 3 · G043
Perfect tenses use a past participle
Have, has and had in perfect constructions must be followed by the past participle, not the simple past form.
Correct example
He has written the summary.
Incorrect example
He has wrote the summary.
Interpretation
Have, has and had in perfect constructions must be followed by the past participle, not the simple past form. In a test, do not memorise this as an isolated sentence. Look at the helper verb first; it determines the form that follows. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.
Why it matters
Auxiliaries sharply restrict the form that can follow, making these high-confidence marks once the pattern is recognised.
Common exam trap
Adding tense twice: once on the auxiliary and again on the main verb.
How to spot it
Mark the time words and order the events. Choose the tense only after the timeline is clear.
3-step solving method
- Circle the auxiliary or trigger.
- Write the form it requires (base/-ing/past participle).
- Check that tense is not marked twice.
Why the incorrect example fails
The target structure requires this rule: Have, has and had in perfect constructions must be followed by the past participle, not the simple past form. In the incorrect version, the repair is to replace “wrote” with “written”. That is the exact edit a student should be able to justify in an error-spotting question.
Nuance and memory hook
Do not identify a form only by its spelling; the same -ed or -ing form can perform different grammatical jobs.
HAVE + past participle.
Quick check
Without relying on what 'sounds right', explain which part of this sentence violates the rule: “He has wrote the summary.”
Reveal quick check answer
Apply Perfect tenses use a past participle: Have, has and had in perfect constructions must be followed by the past participle, not the simple past form.
Practice questions
Apply the rule in context
Which sentence is the better choice in standard exam-oriented English?
Explain the error rather than guessing by sound
Why is this sentence problematic in the target rule? “He has wrote the summary.”
Rule 4 · G044
Continuous tenses use be + present participle
Continuous forms combine an appropriate form of be with the -ing form of the main verb.
Correct example
They are preparing for the interview.
Incorrect example
They are prepare for the interview.
Interpretation
Continuous forms combine an appropriate form of be with the -ing form of the main verb. In a test, do not memorise this as an isolated sentence. Look at the helper verb first; it determines the form that follows. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.
Why it matters
Auxiliaries sharply restrict the form that can follow, making these high-confidence marks once the pattern is recognised.
Common exam trap
Adding tense twice: once on the auxiliary and again on the main verb.
How to spot it
Mark the time words and order the events. Choose the tense only after the timeline is clear.
3-step solving method
- Circle the auxiliary or trigger.
- Write the form it requires (base/-ing/past participle).
- Check that tense is not marked twice.
Why the incorrect example fails
The target structure requires this rule: Continuous forms combine an appropriate form of be with the -ing form of the main verb. In the incorrect version, the repair is to replace “prepare” with “preparing”. That is the exact edit a student should be able to justify in an error-spotting question.
Nuance and memory hook
Do not identify a form only by its spelling; the same -ed or -ing form can perform different grammatical jobs.
BE + -ing.
Quick check
Without relying on what 'sounds right', explain which part of this sentence violates the rule: “They are prepare for the interview.”
Reveal quick check answer
Apply Continuous tenses use be + present participle: Continuous forms combine an appropriate form of be with the -ing form of the main verb.
Practice questions
Apply the rule in context
Which sentence is the better choice in standard exam-oriented English?
Explain the error rather than guessing by sound
Why is this sentence problematic in the target rule? “They are prepare for the interview.”
Rule 5 · G045
Passive voice uses be + past participle
The passive normally combines a form of be with the past participle of the lexical verb.
Correct example
The results were announced yesterday.
Incorrect example
The results were announce yesterday.
Interpretation
The passive normally combines a form of be with the past participle of the lexical verb. In a test, do not memorise this as an isolated sentence. Look at the helper verb first; it determines the form that follows. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.
Why it matters
Auxiliaries sharply restrict the form that can follow, making these high-confidence marks once the pattern is recognised.
Common exam trap
Adding tense twice: once on the auxiliary and again on the main verb.
How to spot it
Mark the time words and order the events. Choose the tense only after the timeline is clear.
3-step solving method
- Circle the auxiliary or trigger.
- Write the form it requires (base/-ing/past participle).
- Check that tense is not marked twice.
Why the incorrect example fails
The target structure requires this rule: The passive normally combines a form of be with the past participle of the lexical verb. In the incorrect version, the repair is to replace “announce” with “announced”. That is the exact edit a student should be able to justify in an error-spotting question.
Nuance and memory hook
Do not identify a form only by its spelling; the same -ed or -ing form can perform different grammatical jobs.
BE + past participle; the receiver becomes the grammatical focus.
Quick check
Without relying on what 'sounds right', explain which part of this sentence violates the rule: “The results were announce yesterday.”
Reveal quick check answer
Apply Passive voice uses be + past participle: The passive normally combines a form of be with the past participle of the lexical verb.
Practice questions
Apply the rule in context
Which sentence is the better choice in standard exam-oriented English?
Explain the error rather than guessing by sound