Study · Academic grammarModule 08
Modal Verbs for Academic Caution and Certainty
Level B1–B2
Learning goals
- In this module, you will learn how modal verbs communicate different levels of certainty and strength. You will practise choosing forms that make academic claims appropriately careful, precise and well supported.
Step 1 — Read and discover
Read the passage. Notice how the bold structures show possibility, cautious interpretation, or a stronger conclusion.
Why do some public spaces attract more visitors?
A city research team examined how people use three public squares. The team expected that squares with more benches would attract more visitors, but the results were not so simple. The busiest square had fewer benches than another site. This may suggest that seating is only one factor in how people choose a place to spend time.
The researchers noted that shade could be important during hot weather. However, the study took place in spring, so the team cannot conclude that the same pattern would appear in summer. Other factors, including nearby shops and public transport, might also influence visitor numbers. The team should consider these factors in a later study.
The findings must be interpreted carefully because observations were made on only six days. A larger sample could provide a clearer picture, and future research may reveal whether the same results occur in other neighbourhoods. The team argues that planners should not assume that one design will work equally well everywhere. Instead, local conditions need to be considered before changes are made.
Check your understanding
1. Why does the team avoid a firm conclusion about summer?Try again
1. Why does the team avoid a firm conclusion about summer?
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2. What does “may suggest” communicate in the passage?Try again
2. What does “may suggest” communicate in the passage?
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3. What does the team recommend planners do?Try again
3. What does the team recommend planners do?
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Step 2 — Understand the grammar
Study the grammar cards for the key modal verbs and expressions, then continue to the exercises.
Grammar cards
may
modal verbB1–B2Expresses possibility or a cautious interpretation.
“The results may indicate a change in public behaviour.”
- may indicate
- may suggest
- may affect
Word family: might, may have + past participle
Use may when a claim is possible but not certain.
might
modal verbB1–B2Expresses possibility, often with a cautious tone.
“The difference might reflect the age of the participants.”
- might reflect
- might explain
- might influence
Word family: might have + past participle
Might is often similar to may in academic writing.
could
modal verbB1–B2Expresses possibility or a potential ability or option.
“A larger sample could provide more reliable evidence.”
- could provide
- could explain
- could improve
Word family: could have + past participle
Could does not mean that something definitely happened.
must
modal verbB1–B2Expresses strong obligation or, in some contexts, a strong logical conclusion.
“Researchers must report any important limitations.”
- must report
- must consider
- must protect
Word family: must have + past participle
Use carefully: must is much stronger than may or might.
should
modal verbB1–B2Expresses advice, expectation, or a recommended action.
“Future studies should examine the issue over a longer period.”
- should examine
- should consider
- should be treated
Word family: should have + past participle
Should often presents a recommendation rather than a strict rule.
cannot
modal verbB1–B2Expresses inability or states that evidence does not support a conclusion.
“These data cannot establish a causal relationship.”
- cannot establish
- cannot confirm
- cannot rule out
Word family: cannot have + past participle
In academic claims, cannot may identify a limit of the evidence.
need to
semi-modal expressionB1–B2Expresses necessity.
“The analysis needs to account for missing responses.”
- need to account for
- need to consider
- need to distinguish
Word family: needed to
Need to is followed by the base form of a verb.
ought to
modal expressionB1–B2Expresses advice or a strong recommendation.
“Researchers ought to explain how the sample was selected.”
- ought to explain
- ought to consider
- ought to include
Word family: ought to have + past participle
Ought to is less common than should in modern academic prose.
have to
semi-modal expressionB1–B2Expresses necessity, often because of a rule or circumstance.
“The team has to remove duplicate entries before analysis.”
- have to remove
- have to follow
- has to meet
Word family: had to
The form changes with the subject and tense.
be likely to
adjective + infinitiveB1–B2Expresses that something has a high probability of happening.
“The revised method is likely to reduce measurement errors.”
- is likely to reduce
- likely to affect
- more likely to occur
Word family: likelihood
Likely expresses probability, not certainty.
be unlikely to
adjective + infinitiveB1–B2Expresses that something probably will not happen.
“The result is unlikely to apply to every region.”
- unlikely to apply
- unlikely to explain
- less likely to occur
Word family: unlikely
Do not confuse unlikely with impossible.
may have
modal perfectB1–B2Expresses a possible past event or explanation.
“The team may have overlooked a relevant variable.”
- may have overlooked
- may have affected
- may have resulted
Word family: might have + past participle
Use a past participle after have.
might have
modal perfectB1–B2Expresses a possible past event, often cautiously.
“The change might have resulted from a measurement error.”
- might have resulted
- might have influenced
- might have been
Word family: might have + past participle
It does not state that the event definitely happened.
could have
modal perfectB1–B2Expresses a possible past explanation or an unrealised possibility.
“The repeated measurements could have reduced random error.”
- could have reduced
- could have contributed
- could have been
Word family: could have + past participle
The context determines whether it refers to a possible explanation or an unrealised option.
must have
modal perfectB1–B2Expresses a strong deduction about a past event.
“The sensor must have failed because every reading stopped at the same time.”
- must have failed
- must have affected
- must have occurred
Word family: must have + past participle
Use only when the evidence strongly supports the deduction.
should not
modal phraseB1–B2Expresses advice against an action or a claim that is not advisable.
“Researchers should not generalise from such a small sample.”
- should not generalise
- should not assume
- should not ignore
Word family: should not have + past participle
Should not is a recommendation, not always a prohibition.
do not necessarily
negative adverbial phraseB1–B2Shows that a statement is not always or automatically true.
“Consistent results do not necessarily prove the proposed explanation.”
- do not necessarily prove
- does not necessarily mean
- not necessarily indicate
Word family: necessarily
This phrase weakens an overgeneralised claim without saying it is false.
be required to
passive adjective phraseB1–B2Expresses a formal requirement.
“Applicants are required to provide informed consent.”
- are required to provide
- is required to report
- required to submit
Word family: requirement
Often used in formal procedures, rules, and research ethics.
be permitted to
passive adjective phraseB1–B2Expresses permission.
“Participants are permitted to withdraw at any time.”
- are permitted to withdraw
- permitted to access
- be permitted to use
Word family: permission
A formal alternative to be allowed to.
be expected to
passive adjective phraseB1–B2Expresses an expectation or a predicted pattern.
“The revised model is expected to improve prediction accuracy.”
- is expected to improve
- expected to increase
- be expected to produce
Word family: expectation
Expected to does not guarantee that the outcome will occur.
Step 3 — Meaning in context
Choose the best answer, then check your choices.
1. The results _may indicate_ a connection between shade and visitor numbers.Try again
1. The results _may indicate_ a connection between shade and visitor numbers.
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2. Researchers _must report_ any important limitations.Try again
2. Researchers _must report_ any important limitations.
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3. The pattern _could be explained_ by differences in transport access.Try again
3. The pattern _could be explained_ by differences in transport access.
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4. The evidence _cannot establish_ that the policy caused the change.Try again
4. The evidence _cannot establish_ that the policy caused the change.
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5. The sample is small, so the findings _should be treated_ with caution.Try again
5. The sample is small, so the findings _should be treated_ with caution.
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Step 4 — Complete the sentences
Type the missing word or phrase. More than one answer may be accepted when it fits the sentence.
1.The results are preliminary, so they indicate a wider trend.Try again✓
2.Researchers distinguish correlation from causation.Try again✓
3.This difference be related to the age of the participants.Try again✓
4.The survey included only one town; therefore, it represent the whole country.Try again✓
5.Future studies examine the issue over a longer period.Try again✓
6.The figures are incomplete, so we draw a firm conclusion yet.Try again✓
7.Local authorities provide clear information about the project.Try again✓
8.The unexpected result have occurred because of a measurement error.Try again✓
Step 5 — Choose the correct form
Choose the best correction or answer.
1. The evidence is limited, so the claim ___ be accepted without further testing.Try again
1. The evidence is limited, so the claim ___ be accepted without further testing.
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2. The figures are consistent with the theory, but they ___ prove it.Try again
2. The figures are consistent with the theory, but they ___ prove it.
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3. Researchers ___ have overlooked a relevant variable, although this is not certain.Try again
3. Researchers ___ have overlooked a relevant variable, although this is not certain.
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4. Because the procedure was repeated, the team ___ compare the results more reliably.Try again
4. Because the procedure was repeated, the team ___ compare the results more reliably.
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5. The report ___ include the method so that readers can evaluate the findings.Try again
5. The report ___ include the method so that readers can evaluate the findings.
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Step 6 — Match the beginnings and endings
Match each beginning with the best ending.
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4. ✓
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Step 7 — Quick review
Choose the best answer for each question.
1. Which phrase expresses a cautious possibility?Try again
1. Which phrase expresses a cautious possibility?
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2. Which sentence expresses a strong obligation?Try again
2. Which sentence expresses a strong obligation?
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3. Which sentence is the most cautious conclusion?Try again
3. Which sentence is the most cautious conclusion?
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4. What is the best advice when evidence is incomplete?Try again
4. What is the best advice when evidence is incomplete?
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5. Which form is grammatically correct?Try again
5. Which form is grammatically correct?
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