Level 1 — Foundation · Clauses & Paragraph Architecture
Lesson 17: Modals, Hedging & Degree of Certainty
'Stress causes poor decisions', 'Stress may cause poor decisions', and 'Stress may contribute to poor decisions' are three different claims — how to read modals and hedging language for exactly how confident the author actually is.
Learning Objectives
By the end of this lesson, you should be able to:
- Read may/might/could/can as a rough scale of possibility, and must/should/will/would by their specific function
- Recognise hedging phrases (is associated with, appears to, tends to, may contribute to) and understand why academic writers reach for them
- Distinguish association from causation, and recognise when a sentence claims only the weaker of the two
- Separate a sentence's content — what is claimed — from its certainty — how confidently it's claimed
- Extract every layer of hedging stacked inside a single dense academic sentence
Introduction
Today's goal is to read past a sentence's plain factual content and notice how certain, uncertain, cautious, or strong the author actually is. This matters enormously in academic books, psychology, science, history, business, research papers, and non-fiction generally.
The Same Idea, Different Certainty
One small word can completely change a claim's strength
Stress causes poor decisions. — a strong claim: stress definitely causes poor decisions.
Stress may cause poor decisions. — a possibility: stress can cause poor decisions.
Stress may contribute to poor decisions. — even more cautious: stress may play a role in poor decisions.
One small word — may — has completely changed the claim's strength.
What Is a Modal Verb?
Common modals: can, could, may, might, must, should, will, would. They sit directly before a main verb.
People can change. · Stress may affect memory. · Researchers could be wrong. · The evidence might support the theory. · This result must be interpreted carefully.
"May" — Possibility
The most common academic modal
Stress may affect decision-making.
The author is not claiming stress definitely affects decision-making — only that it's possible.
"Might" — A More Uncertain Possibility
A slightly more tentative possibility
Stress might affect decision-making.
Roughly: may → possibility. might → a somewhat more tentative possibility. In real English, though, the difference between may and might isn't always sharp — context matters more than the word choice alone.
"Could" — Possibility / Potential
Possible, or potentially able to
Stress could affect decision-making. — could = possible/potential.
This method could improve reading comprehension. — a future potential.
"Can" — General Possibility / Ability
A general capability, not a specific instance
Stress can affect decision-making. — generally speaking, this can happen.
Compare: Stress may affect decision-making. → possibility in this particular situation. Stress can affect decision-making. → generally, this kind of thing can happen.
May / Might / Could — A Rough Reading Scale
definitely
↓
probably
↓
likely
↓
may / could
↓
might / possibly
Treat this as a ladder, not a ruler: it tells you which direction a word moves the certainty, not an exact, measurable amount.
"Must" — Strong Necessity
A passive + modal combination
The evidence must be examined carefully.
must + be + V3 = passive + modal. Meaning: examining the evidence carefully is necessary.
But must has a second, very different job:
He must be tired. — here must signals a strong logical inference: he is surely tired.
Must's Two Functions
Obligation vs. deduction — check the context
A. Obligation: Researchers must follow the procedure. — following the procedure is required.
B. Deduction: The researchers must have noticed the problem. — the author is confidently inferring that they surely noticed it.
Context tells you which function is intended.
"Should" — Advice / Expectation
Two different jobs for the same modal
Advice: Researchers should consider alternative explanations. — researchers ought to consider them.
Expectation: The results should be available tomorrow. — not advice; this means the results are expected, probably, to be available tomorrow.
"Will" — Prediction / Strong Expectation
A confident prediction
The situation will change. — a prediction.
These changes will affect future research. — a relatively strong academic prediction.
"Would" — Hypothetical / Reported Future / Expected Result
Callback to Lesson 12's conditionals
If people had more information, they would make better decisions. — would = a hypothetical result.
He said that the situation would change. — reported speech, viewing a future event from a past perspective.
"Likely"
be likely to + verb
The results are likely to vary.
Meaning: there's a good chance the results will vary.
Pattern: be likely to + verb — is likely to affect · are likely to change · is likely to increase · are likely to influence.
"Unlikely"
unlikely does not mean impossible
The results are unlikely to change. — a low probability of change.
unlikely ≠ impossible. This distinction matters — don't read unlikely as a flat denial.
"Probably"
A relatively high probability, but not certainty
The results will probably change.
Compare: The results will change. (a flat prediction) vs. The results will probably change. (a more cautious version of the same prediction).
"Possibly"
Raising uncertainty further
The results could possibly change.
possibly adds an extra layer of uncertainty on top of could.
"Certainly" and "Clearly"
These signal the author's stance, not objective proof
Certainly: The evidence certainly supports the conclusion. — the author is very confident.
Clearly: The results clearly demonstrate the effect. — the author is asserting that the evidence is obvious or strong.
But in critical reading, don't assume clearly being written means the evidence is objectively, undeniably clear — it's the author's stance, not an independent guarantee.
"Apparently"
Based on available information, but not fully confirmed
Apparently, the researchers were unaware of the problem.
Meaning: based on the information available, this seems to be true. The author is making a claim without taking on full, direct certainty.
"Arguably"
A defensible interpretation, not the only possible one
The most important factor is arguably experience.
Meaning: a reasonable case can be made that experience is the most important factor — but the author isn't claiming this is the only possible interpretation.
"Tends To"
A tendency, not a universal rule
People tend to rely on familiar information.
The author is not saying people always rely on familiar information — only that there's a general tendency.
Compare: People rely on familiar information. (a general statement) vs. People tend to rely on familiar information. (a tendency, not a universal rule).
"Appears To"
Cautious academic language
The method appears to be effective.
Meaning: based on available evidence, the method seems to be effective — cautious, not a flat assertion.
"Seems To"
Reducing certainty explicitly
The results seem to indicate a relationship.
Meaning: the results appear to indicate a relationship — the author has deliberately lowered the certainty here.
"Is Associated With"
A crucial phrase, especially in psychology and science — association is not causation
Stress is associated with poor sleep.
Meaning: stress and poor sleep are found together, statistically. This does not automatically claim: stress causes poor sleep.
Association ≠ causation. X and Y occur together is a much weaker claim than X definitely causes Y.
"May Be Associated With"
Two layers of caution, stacked
Stress may be associated with poor sleep.
may → uncertainty. be associated with → a relationship, not necessarily causation. Together, these make an already-cautious claim even more cautious.
"Has Been Shown To"
Passive reporting, source often left implicit
The method has been shown to improve performance.
has been shown (passive) + to improve (infinitive). Meaning: studies/evidence have demonstrated this — but exactly who showed it often has to be worked out from context.
"Is Believed To" / "Is Thought To" / "Is Considered To Be"
Three interchangeable shapes for an unnamed source's view
All three follow the same pattern — be + reporting verb (passive) + to + verb — and all three let a writer report a widely-held view without naming exactly who holds it.
The treatment is believed to improve memory. — roughly equivalent to Researchers believe that the treatment improves memory, but as a passive, the focus stays on treatment, and the believer stays unnamed.
The behavior is thought to reflect social learning. — same shape: someone thinks this, but the sentence never says who.
The method is considered to be effective. — is considered (passive reporting) + to be effective (infinitive); again, no named source.
Treat all three as one recognisable pattern rather than three separate verbs to memorise.
A Master Map of Certainty Expressions
| Strength | Examples |
|---|---|
| Very strong | definitely · certainly · clearly · must |
| Strong/moderate | likely · probably · will · is expected to |
| Cautious | may · could · might · possibly · appears to · seems to · tends to |
| Very cautious / qualified | may contribute to · may be associated with · is sometimes interpreted as · could potentially · arguably |
Once again, this is a rough reading guide, not an absolute scale.
What Is Hedging?
Connecting back to Lesson 9: you met hedging there through degree and certainty words; here the focus shifts to the specific modal and passive-reporting shapes that carry it.
Formulating a claim so it doesn't overstate certainty
Strong: Exercise improves memory. Hedged: Exercise may improve memory. More hedged: Exercise may contribute to improvements in memory. Even more cautious: Exercise may be associated with better memory performance.
Why Academic Writers Hedge
Because evidence is rarely simple or complete
Scientific evidence is often limited, incomplete, context-dependent, probabilistic, based on one sample, and open to alternative explanations.
So writing "X may contribute to Y" instead of "X always causes Y" is often the more scientifically responsible choice.
"Not Necessarily"
Callback to Lesson 12 — a very subtle, very important phrase
More information does not necessarily lead to better decisions.
Meaning: having more information doesn't guarantee better decisions.
Compare: More information does not lead to better decisions. (a stronger, flat negative claim) vs. More information does not necessarily lead to better decisions. (leaves room for exceptions).
"Generally"
Weaker than 'always'
People generally prefer familiar options.
Meaning: as a general pattern, people prefer familiar options — weaker than always.
"Often"
Frequent, not universal
People often rely on shortcuts. — frequently.
People always rely on shortcuts. — universally.
These are not the same claim.
Frequency and Certainty, Stacked Together
Multiple layers of caution in one short sentence
People often tend to rely on familiar information.
often → frequency. tend to → tendency. Together, this is far from a strong, universal claim.
Today's Mega Sentence
Multiple levels of caution in a single academic sentence
The available evidence suggests that stress may contribute to poorer decision-making, although the relationship is unlikely to be simple and may depend on the type of decision being made.
Source: the available evidence. Reporting verb: suggests (cautious). Main claim: stress may contribute to poorer decision-making. may → possibility.
Contrast: although. Certainty: is unlikely to be simple — low probability of simplicity. Condition/context: may depend on… — the relationship might be context-dependent.
The author has layered several levels of caution into one sentence.
Extracting the "Certainty Layer"
Separating what is claimed from how confidently
Researchers strongly argue that the results probably reflect differences in experience.
strongly → the strength of the argument itself. argue → the reporting stance. probably → the claim's probability. reflect → the actual proposition being made.
Reading only "results reflect differences" would miss most of the sentence's real information.
Separating the Author's Confidence
Two sentences, two very different confidence levels
The results clearly demonstrate that the method is effective. — author confidence: very high.
The results appear to suggest that the method may be effective. — author confidence: much lower. Two hedges stacked here: appear to suggest and may be effective.
"Could" Is Not Always Weak Certainty
Check which of could's several jobs is in play
The new system could reduce costs. — potential.
He could have forgotten the meeting. — past possibility.
When he was younger, he could run 10 kilometers. — past ability.
A modal's function depends on context — never assume a fixed meaning from the word alone.
Today's Reading Method
Label every modal or hedge you meet
Applying the labels
The method may improve performance. → POSSIBILITY. Researchers must consider alternative explanations. → OBLIGATION. The results are likely to vary. → HIGHER PROBABILITY. The findings appear to suggest a relationship. → CAUTIOUS CLAIM.
Vocabulary in Context
tendencynoun
a general pattern of behaving or happening a certain way, without being universal (প্রবণতা)
“There is a tendency to rely on familiar information when time is limited.”
probabilitynoun
how likely something is to happen or be true (সম্ভাবনা)
“The probability of a different outcome cannot be ruled out.”
certaintynoun
the state of being completely sure about something (নিশ্চয়তা)
“Scientific findings are rarely stated with complete certainty.”
cautiousadjective
careful to avoid stating more than the evidence supports (সতর্ক)
“A cautious writer says a factor 'may contribute to' an outcome, not that it causes it.”
qualifyverb
to limit or add a condition to a statement so it isn't taken as absolute (সীমিত করা)
“Academic writers often qualify a claim with a word like 'may' or 'tends to'.”
Chunks worth learning as whole units
may affect · may contribute to · might explain · could lead to · could result in · is likely to · is unlikely to · appears to be · seems to indicate · tends to · is associated with · may be associated with · is believed to · is thought to · is considered to be · has been shown to · is expected to · does not necessarily mean · generally accepted · probably reflects · potentially useful · arguably important
Guided Reading Practice
Read the paragraph once, slowly, tracking every hedge and modal.
Research suggests that people may not always make decisions in a fully rational manner. Individuals often rely on mental shortcuts, which can sometimes help them make decisions quickly but may also lead to errors. These shortcuts are likely to be particularly useful when people have limited time or information. However, they may be less effective in situations that require careful analysis. Some researchers argue that training could help people recognize situations in which these shortcuts are likely to produce poor outcomes, although it is unlikely that such training would eliminate biased decision-making completely.
1 — Source: Research. Reporting verb: suggests. Claim: people may not always make decisions rationally. Certainty: suggests + may → cautious.
2 — often → frequency. can sometimes help → possibility + frequency. may also lead to errors → possibility.
3 — are likely to be → relatively high probability.
4 — may be less effective → possibility.
5 — Source: Some researchers. Reporting verb: argue. Claim: training could help… — could → potential.
6 — unlikely → low probability. would eliminate → hypothetical result. The author has deliberately limited the claim: training could help, but is unlikely to eliminate completely — improving is not the same as completely solving.
Golden Rule
Golden Rule
Never stop at "what does this sentence say?" Always ask a second question: "how certain is the author that it's true?" Content and certainty are two separate pieces of information — read them both.
Content: Stress may affect memory. Certainty: may → possibility, not certainty. Both matter equally.
Lesson Summary
Today you learned to read may, might, could, can as a rough possibility scale, and must, should, will, would by their specific function — obligation, deduction, advice, expectation, prediction, or hypothetical result. You met the crucial distinction between association and causation, practised recognising hedging phrases like appears to, tends to, and may be associated with, and understood why academic writers reach for caution rather than absolute claims. Most importantly, you practised separating a sentence's content from its certainty — two different pieces of information carried by the same sentence.
Practice: Test What You've Learned
Work through every question yourself before checking anything.
Before you start
Do not use Google Translate or any other translation tool for these questions. Underestimating or overestimating an author's certainty is the exact mistake today's lesson is designed to catch.
Part A — Modal Function
Identify each modal's function.
- Stress may affect memory.
- Researchers must consider alternative explanations.
- The method could improve performance.
- The results should be available tomorrow.
- He must be tired.
Part B — Certainty
Which is more cautious?
- A: The results show that the method works. — B: The results suggest that the method may work.
- A: Stress causes poor decisions. — B: Stress may contribute to poorer decisions.
Part C — Meaning
- What does "The results are unlikely to change" mean?
- What is the exact logical meaning of "This does not necessarily mean that the theory is wrong"?
Part D — Reading Analysis
- Decode this sentence: The available evidence appears to suggest that the treatment may be effective, although further research is likely to be necessary. Identify: the source, the reporting/stance expression, the main claim, hedge 1, hedge 2, the probability expression, and the contrast connector.
Part E — Advanced
- Explain the difference between "Stress is associated with poor sleep" and "Stress causes poor sleep," and explain why the first is often more appropriate in scientific/academic writing.
Next: Lesson 18 — Nominalization & Dense Academic English: how "The implementation of the policy resulted in a significant reduction in costs" compresses "The company implemented the policy, and costs fell significantly," and how to take that compression apart.