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Evidentiality Strategies in English

English has no inflectional endings that obligatorily identify the source of knowledge. Speakers can mark it through verbs: saw, heard and felt report direct perception, while looks, sounds and smells as if present an inference. Practise choosing between them, forming complements after perception verbs, and accurately distinguishing an observed event from an assumption.

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Sensory evidence: what you perceived and what you infer from appearance, sound or smell

Verb choice identifies the source of knowledge

English has no grammatical endings specifically marking meanings such as “I witnessed this” or “someone told me this”. Speakers express the source through vocabulary, so a perception verb can also indicate how they know something.

With direct perception, speakers identify themselves as the person who saw, heard, felt or noticed an event. With inference, they perceive signs and state what follows from those signs. These represent different kinds of commitment to the claim.

I smelled rubber burning as I came in.

I smelled rubber burning as I came in.

Direct perception: the speaker personally experienced the smell.

We watched the tide go out.

We watched the tide go out.

Direct observation presenting the event as a whole.

The lake looks frozen.

The lake looks frozen.

An impression based on appearance, not a verified fact.

Direct perception: what is the speaker testifying to?

See, hear, feel, notice and watch can take an object followed by a base verb or an -ing form. The base form often presents an event as a whole; -ing highlights its progress. This is a way of representing the event, not a guarantee that the observer literally witnessed every instant from beginning to end.

For a directly perceived event, active see / hear + object normally takes leave, not to leave. In the passive, She was seen to enter is possible. A by-phrase can name the observer; leaving the observer unnamed does not itself mean the speaker was not a witness. Other meanings, such as understanding, may use different constructions.

For ordinary visual or auditory perception, can / could see and can / could hear are natural. Progressive forms are less typical for a simple state, but are possible in special contexts, such as a new or repeated experience. There is no universal ban on am seeing.

How to build it

perception verb + object + base verb without to (event as a whole) / -ing form (event in progress)

verb / V
—
A word for an action or state, such as work or be. The pattern determines its form.
V1 / base form
—
The base verb without to: work, go, be.
V-ing / -ing
—
The verb form ending in -ing: working, going. Its role depends on the construction.
object / O
—
Who or what an action affects: in I read a book, a book is the object.

She felt the bridge sway.

She felt the bridge sway.

The base form sway presents the movement as a whole. There is no need to prove that the observer felt every moment of it.

From the platform we heard a train approaching.

From the platform we heard a train approaching.

The event is perceived in progress.

I could see lights moving across the field.

I could see lights moving across the field.

Could describes visual perception in the past.

Inference from the senses: look, sound, smell, taste and feel

After look, sound, smell, taste and feel, we can describe an impression. Three patterns are available: an adjective, as in looks frozen; like + noun phrase, as in sounds like a rehearsed speech; and as if / as though + clause, as in smells as though rain is coming.

Use an adjective rather than an adverb: sounds angry, not sounds angrily. Like + clause is also possible after these verbs in conversation, while as if and as though are more neutral in register.

In the clause after as if, speakers usually choose the tense that matches their assumption about the real situation: a present form for now, or a past or perfect form for an earlier event.

How to build it

it + looks / sounds / smells + as if / as though / like + clause

clause
—
A construction with a verb, often with its own subject: when I arrived. A non-finite clause may leave the subject unspoken: to get home.

Her excuse sounds like a rehearsed speech.

Her excuse sounds like a rehearsed speech.

Like + noun phrase.

He looked as if he had been awake all night.

He looked as if he had been awake all night.

As if + a clause in Past Perfect.

The air smells as though rain is coming.

The air smells as though rain is coming.

An inference based on smell.

The same sensory channel, a different claim

The same sensory experience can lead to different formulations. I could hear the printer jamming reports hearing the process. It sounds as though the printer is jammed reports a sound and infers its cause. The second version is less categorical.

These presentations are not always interchangeable. Identify what you perceived directly and what you infer from signs. However, a speaker can see signs of an event and cautiously describe its result. Looks as if does not by itself imply dishonesty or inappropriate understatement of evidence.

I saw the delegates sign the treaty.

I saw the delegates sign the treaty.

The speaker testifies to witnessing the event.

The delegates seem to have signed the treaty.

The delegates seem to have signed the treaty.

The speaker infers the event from signs.

Source phrases: by the look of it, from the sound of it

Phrases such as by the look of it, from the sound of it and judging by the smell explicitly name the sensory basis of an inference. They can appear at the beginning or end of a sentence, set off with a comma.

Such a phrase states the basis without claiming that the speaker saw or heard the event itself. It is useful when you want to identify the source while leaving room for doubt.

By the look of the sky, we are in for a storm.

By the look of the sky, we are in for a storm.

An inference from appearance.

Judging by the smell, dinner is nearly ready.

Judging by the smell, dinner is nearly ready.

An inference from smell.

From the feel of the fabric, it must be silk.

From the feel of the fabric, it must be silk.

An inference from touch.

Form and register

Meaning and context determine tense and aspect. Tastes bitter describes a property; is tasting the wine describes deliberate sampling. At the same time, I’m feeling better and You’re looking tired can describe a current state. Do not impose a blanket ban on progressive forms with impression verbs.

Looks like + clause is common in conversation; as if / as though often suit more formal writing. The passive was seen to is useful when the observed person is the focus. Replace it with I saw him only if I was actually the observer.

Dad is tasting the stew to check the salt.

Dad is tasting the stew to check the salt.

A dynamic meaning permits the progressive form.

The sauce tastes slightly bitter.

The sauce tastes slightly bitter.

A stative meaning uses an adjective and a simple-tense verb.

He was seen to hesitate at the door.

He was seen to hesitate at the door.

A formal passive construction with to.

Boundaries: where sensory evidence ends

Not every use of see or hear refers to the senses. I see your point means I understand it, while I hear the café has new owners reports information from others. The first concerns understanding; the second concerns reporting. Reportedly, allegedly and is said to belong to a separate topic.

Markers of logical inference without a sensory basis, such as must have, evidently and it follows that, also fall outside the sensory focus. Here we practise cases where appearance, sound, smell, taste or touch supplies the evidence.

I see your point.

I see your point.

See means understand here, not perceive visually.

I hear the café has new owners.

I hear the café has new owners.

Hear + clause reports received information here, rather than direct auditory perception of an event.

Common mistakes

Incorrect:He sounds nervously on the radio.

Correct:He sounds nervous on the radio.

Use an adjective after this linking sense of sound. It describes the impression, not the manner of speaking.

Incorrect:I can seeing smoke over the hills.

Correct:I can see smoke over the hills.

The modal can requires the base form see. Am seeing is not forbidden in every context, but can see gives the ordinary description of what is visible here.

Incorrect:I saw him to leave the building.

Correct:I saw him leave the building.

In this active direct-perception construction, use a bare infinitive after the object, not a to-infinitive.

Incorrect:It sounds like if they are quarrelling.

Correct:It sounds as if they are quarrelling.

Like if is not the linking expression needed here. Use as if, or like without if.

Incorrect:This smells as burnt toast.

Correct:This smells like burnt toast.

Use like, not as, before the noun phrase in this comparison.

Incorrect:He sounds like very tired.

Correct:He sounds very tired.

Like introduces a noun phrase or a clause here. Do not put it before the adjective phrase very tired.

Sources

Marking reported information and other people’s words

1. The idea: reporting rather than vouching

English has no obligatory grammatical system requiring speakers to indicate how they know a fact. Instead, information sources are identified through words: adverbs, passive constructions, impersonal expressions and direct source attribution. This is called reportative marking.

A marker helps distinguish a report’s content from its source. It may indicate distance or simply accurate attribution: the speaker may fully trust the source. It is neither an automatic disclaimer of responsibility nor proof that the information is false.

This rule practises reported words specifically: news, rumours, allegations and statements in documents. Impressions from observation, such as looks like, and deductions from clues, such as must have, belong to related rules on sensory and inferential markers. We identify the boundary without teaching those patterns here.

How to build it

source marker + statement → clear attribution of the report

The new bridge is reportedly three months behind schedule.

The new bridge is reportedly three months behind schedule.

Reportedly identifies reports as the source. It neither proves the figure nor releases the writer from accurate reporting.

Allegedly, the mayor knew about the contract from the start.

Allegedly, the mayor knew about the contract from the start.

Allegedly adds the sense of an allegation: the implied wrongdoing has not been proven.

According to the harbour authority, the ferry will resume on Monday.

According to the harbour authority, the ferry will resume on Monday.

The source is named, so readers can see whose words these are and whom to consult.

2. Adverbs: reportedly, allegedly, supposedly and purportedly

Reportedly neutrally indicates that information comes from reports. Allegedly primarily concerns unproven allegations or accusations, so it often appears in news about wrongdoing. Supposedly carries a sceptical nuance, suggesting doubt about what is being relayed. Purportedly sounds formal and indicates a claimed status or quality rather than an established one.

Position: the adverb commonly appears at the start, framing the whole statement, or in the middle near an auxiliary or before the main verb: has reportedly decided, reportedly will decide. An initial adverb is followed by a comma. It can also appear at the end as a detached afterthought, where it is less integrated and sounds like an added qualification rather than the report’s initial frame. This is not an error, just a less integrated position.

Apparently can be based on reports or observable clues. Evidently can also assess information learned from different sources; a single adverb does not always identify the channel of knowledge unambiguously. For explicit attribution, name the source or use reportedly.

V1 is the base form, such as decide; V3 is the past participle, such as decided or written. Has and will require different forms, so their patterns are shown separately.

How to build it

subject + has + reportedly + V3; subject + will + reportedly + V1

subject / S
—
The grammatical subject: who or what the clause is about; the verb agrees with it. In The book was written, the book is the subject, although someone else does the action.
V1 / base form
—
The base verb without to: work, go, be.
V3 / past participle
—
The third verb form: worked, gone, seen. Used after have/has or in the passive, for example; it is not always the same as V2.

The museum has reportedly acquired a lost manuscript.

The museum has reportedly acquired a lost manuscript.

In this middle position, the adverb stands between auxiliary has and the main verb.

The painting was allegedly sold twice in one week.

The painting was allegedly sold twice in one week.

Allegedly precedes the participle and emphasises that this is an unproven allegation.

The summit was purportedly cancelled over a seating dispute.

The summit was purportedly cancelled over a seating dispute.

Purportedly is more formal and conveys “it is claimed that…”.

The painting was sold twice in one week, allegedly.

The painting was sold twice in one week, allegedly.

Final allegedly is an afterthought qualifying the status of the same report. Its final position does not necessarily narrow its scope.

3. Passive constructions: is said / reported / believed to…

Reporting verbs such as say, report, believe, think, claim, allege, rumour and understand form passives in which the person or thing being discussed becomes the subject and an infinitive conveys the reported content: The river is reported to be rising. This is useful when the exact speaker is unknown or unimportant.

The infinitive expresses the event’s time relative to the report or belief, not always relative to the present moment of speaking. To be often describes a simultaneous state; to be + -ing a process; and to have + V3 an earlier event. A simple infinitive can also refer to the future with a suitable reporting verb and context. Compare was believed to be ill: the illness relates to that past belief.

Not every reporting verb conveys the same meaning: allege reports an accusation, claim a statement whose truth remains open, and believe or think a general view. Say and report are neutral. Choosing the verb establishes distance much as choosing the adverb does.

How to build it

Subject + be + said / reported / alleged… + to V / to be V-ing / to have V3

subject / S
—
The grammatical subject: who or what the clause is about; the verb agrees with it. In The book was written, the book is the subject, although someone else does the action.
verb / V
—
A word for an action or state, such as work or be. The pattern determines its form.
V3 / past participle
—
The third verb form: worked, gone, seen. Used after have/has or in the passive, for example; it is not always the same as V2.
V-ing / -ing
—
The verb form ending in -ing: working, going. Its role depends on the construction.

The director is rumoured to be negotiating a move abroad.

The director is rumoured to be negotiating a move abroad.

To be negotiating presents negotiations as an ongoing process during the current period, not necessarily at the exact second of speaking.

The manuscript is believed to have been written in the twelfth century.

The manuscript is believed to have been written in the twelfth century.

This is a perfect passive infinitive: the writing occurred before the present report.

Both ministers are said to have objected.

Both ministers are said to have objected.

A perfect infinitive follows are said: the objections occurred earlier.

4. Impersonal expressions: It is claimed that…, There are reports that…

The impersonal construction uses dummy it, a passive reporting verb and a that-clause: It has been alleged that the contract was backdated. Ordinary tense choices operate within the that-clause, so a past event uses a finite form such as was or had been rather than an infinitive.

There are reports that…, Word has it that… and Reports suggest that… also link content to reports. The source may be specified in context; these constructions do not necessarily conceal its author more strongly. Word has it often introduces an unofficial rumour.

It is said that she left and She is said to have left can convey the same essential content. The first reports it in a finite that-clause, the second in an infinitive clause; each can be a single sentence.

In the pattern, be takes the required form, such as is, was or has been; V3 is the participle said, reported, claimed or alleged; and clause means a complete subordinate clause with its own subject and predicate.

How to build it

It + be + V3 (said / reported / claimed / alleged) + that + clause

V3 / past participle
—
The third verb form: worked, gone, seen. Used after have/has or in the passive, for example; it is not always the same as V2.
clause
—
A construction with a verb, often with its own subject: when I arrived. A non-finite clause may leave the subject unspoken: to get home.

It has been alleged that the contract was backdated.

It has been alleged that the contract was backdated.

The impersonal construction is present perfect passive; the that-clause uses an ordinary past tense.

There are reports that the airport will close for a week.

There are reports that the airport will close for a week.

The noun reports identifies the type of source without naming its author.

Word has it that the festival has lost its sponsor.

Word has it that the festival has lost its sponsor.

This is a conversational idiom for passing on a rumour.

5. Named sources and reporting verbs with different degrees of distance

According to names a source: a person, organisation or document. It is compatible with both trust and distance. For your own current opinion, in my view or in my opinion is usually more natural; according to me is possible in a special contrast or when referring to your own earlier words.

Say/report relay information; state emphasises an explicit statement, and announce an announcement. Claim may add distance, while allege often introduces an unproven accusation. State and announce do not automatically mean the narrator endorses the content. Check evidence and attribution separately from the choice of verb.

Present conflicting sources with different subjects: The police report… The hospital, however, says…. This allows the speaker to report both without taking sides or deciding for readers which figure is correct.

How to build it

According to + source, + clause; source + claims/states/alleges + that + clause

clause
—
A construction with a verb, often with its own subject: when I arrived. A non-finite clause may leave the subject unspoken: to get home.

According to the forecast, the heatwave will end by Friday.

According to the forecast, the heatwave will end by Friday.

The forecast is an identifiable source that can be checked, so neutral attribution is appropriate.

The agency claims that its audit was independent.

The agency claims that its audit was independent.

Claim leaves the question of truth open.

Witnesses allege that the guard left his post.

Witnesses allege that the guard left his post.

Allege reports an accusation that has not yet been proven.

6. Boundaries: a report, your own observation or your own inference

Distinguish observation, reporting and inference, while remembering that they can combine. A telephone check confirms that someone answered you; the answer’s content still came from another person. Source and degree of certainty are related but separate questions.

You can name another source even after checking something yourself, for precision or to compare information. Reportedly + is said to can be redundant, but several markers may represent different links in a reporting chain. Retain only those that clarify the sources and limits of confirmation.

A marker does not make content safe or true; it accurately indicates the information’s status. When several sources disagree, preserve neutral attribution. When a fact is verified, state it directly.

How to build it

someone else’s words → reportative marker; observed directly → sensory description; inferred → inferential marker

The museum is closed today; I have just phoned the front desk.

The museum is closed today; I have just phoned the front desk.

The speaker explicitly names the method of checking. The information about closure may have come from a staff member; it was not directly observed visually.

The shop is reportedly closing, though nobody has said so officially.

The shop is reportedly closing, though nobody has said so officially.

This is a report without official confirmation: one marker frames it, and the second clause adds a direct comment.

The shop looks closed; the shutters are down.

The shop looks closed; the shutters are down.

This is the speaker’s own observation, not a report of someone else’s words.

Common mistakes

Incorrect:The singer said to have cancelled the tour last month.

Correct:The singer is said to have cancelled the tour last month.

The intended passive is said needs a form of be. Said alone can be a finite past-tense active verb, but it does not form the intended passive here without is.

Incorrect:It is claimed the chairman to have lied.

Correct:The chairman is claimed to have lied.

It is claimed requires a finite that-clause; the infinitive pattern instead requires the chairman itself as the subject.

Incorrect:According the forecast, the heatwave will end by Friday.

Correct:According to the forecast, the heatwave will end by Friday.

This pattern introduces the source with according to; the preposition to is required.

Incorrect:The bridge is said to collapse in 1990.

Correct:The bridge is said to have collapsed in 1990.

An event before the present reporting time requires the perfect infinitive to have + V3.

Incorrect:There is reports that the airport will close.

Correct:There are reports that the airport will close.

After there, be agrees with the following noun: plural reports requires are.

Sources

Markers of inference and deduction: showing that a claim comes from evidence

1. Inference as a distinct source of knowledge

When we report something, listeners may implicitly ask how we know it. A language can explicitly mark the source of knowledge. English has no obligatory grammatical marker for this, so speakers choose among modals, adverbs and other constructions.

For this lesson, distinguish direct perception, reported information and inference. In real reasoning, these can combine: an inference may be drawn from someone else’s words or from observed signs.

An inference rests on a basis that is explicit or understood from context. The marker shows how the speaker assesses its strength; it does not prove the conclusion. Even an inference that feels convincing to the speaker can turn out to be wrong.

The ski lift isn't moving and the car park is half empty, so there must have been a fault this morning.

The ski lift isn't moving and the car park is half empty, so there must have been a fault this morning.

The speaker confidently infers a fault earlier that morning. The signs are also compatible with other reasons for the stoppage, so must have does not turn the inference into a verified fact.

I watched the lift stop at ten past nine.

I watched the lift stop at ten past nine.

This reports direct observation. No inference marker is needed.

The operator told us the lift had stopped.

The operator told us the lift had stopped.

This is reported information, a separate topic included here only for contrast.

2. The modal core: must have, must be, can’t have

A common way to mark a confident deduction is must. The form depends on the event’s time. For a present state or ongoing action, use must be + adjective, noun phrase or -ing form. For a completed past event, use must have + past participle.

Can’t / couldn’t have + past participle often rules out a past event. Must not have can also express a negative deduction, particularly in American usage. Context determines the meaning: can’t read can express either inability or disbelief that reading is possible. Perfect forms also have more than one possible interpretation.

Have to and have got to are also sometimes used for deductions, especially in American English. Must expressing obligation is outside this lesson. A bare infinitive follows must: must has and must left are not possible forms.

V3 means past participle, such as left, gone or written. V-ing means an -ing form, such as working. Must + base verb can also describe a general situation: She must know the answer. Be is not required after every must.

How to build it

must be + state / V-ing (present) · must have + past participle (past) · can’t / couldn’t have + past participle (past event ruled out)

verb / V
—
A word for an action or state, such as work or be. The pattern determines its form.
V3 / past participle
—
The third verb form: worked, gone, seen. Used after have/has or in the passive, for example; it is not always the same as V2.
V-ing / -ing
—
The verb form ending in -ing: working, going. Its role depends on the construction.

The bakery's shutters are down and the ovens are cold, so the baker must be on holiday.

The bakery's shutters are down and the ovens are cold, so the baker must be on holiday.

Must be + a state expresses a deduction about the present.

The parcel can't have arrived yet; the tracking page shows it is still in Rotterdam.

The parcel can't have arrived yet; the tracking page shows it is still in Rotterdam.

Can’t have + past participle rules out a past event on the basis of evidence.

Someone is moving furniture upstairs; they must be redecorating.

Someone is moving furniture upstairs; they must be redecorating.

Must be + -ing expresses a deduction about an action in progress now.

3. Inference adverbs: evidently, clearly, obviously, presumably and apparently

Evidently, clearly and obviously present the content as evident to the speaker. The basis may be visible signs or other information. Both obviously and clearly can sound insistent; neither is an automatically polite replacement for the other.

Presumably presents a reasoned assumption that remains open to correction. It may rest on how things usually happen or on specific signs. Visible evidence does not make presumably incorrect: a speaker may deliberately remain cautious.

Apparently is especially ambiguous. It can mark an inference from signs or information that was read or heard. Without context, the word alone does not decide which meaning is intended. Name the evidence nearby when you want an unambiguous inference reading.

The adverb commonly comes at the beginning, separated by a comma, but it can also precede the main verb or appear at the end. It does not determine the verb’s form; normal verb rules still apply.

How to build it

Evidently / Clearly / Obviously / Presumably / Apparently + clause

clause
—
A construction with a verb, often with its own subject: when I arrived. A non-finite clause may leave the subject unspoken: to get home.

Evidently, the lecture hall was double-booked: two groups arrived at the same time.

Evidently, the lecture hall was double-booked: two groups arrived at the same time.

The evidence is stated, and the adverb marks the inference.

Presumably the museum shuts earlier in winter.

Presumably the museum shuts earlier in winter.

This assumption relies on a usual pattern rather than visible evidence.

The deadline has apparently been extended.

The deadline has apparently been extended.

Without context, we cannot tell whether this is an inference or information from another source.

4. Constructions with it and with seem / appear

It would appear that + clause and It seems that + clause present an inference cautiously. Would adds another layer of distance, and it would appear that is characteristic of formal writing.

With a named subject, use seems / appears + infinitive. To have + past participle often places an event before the moment of the impression: appeared to have left. Agreement follows the subject: the tenants seem. A collective noun such as jury can take singular or plural agreement depending on the variety of English and its interpretation.

These constructions do not identify the source. Combine them with explicit evidence when you want the reasoning to be transparent. Perception expressions such as look belong to a different topic and are mentioned only for contrast.

In the formula, X is the subject, V is the base form after to, V3 is the past participle, and clause is a complete subordinate clause. It would appear that the archive moved and The archive appears to have moved differ in structure and temporal perspective. Do not substitute forms mechanically.

How to build it

It would appear / seem that + clause · X seems / appears to + base verb · X seems / appears to have + past participle

verb / V
—
A word for an action or state, such as work or be. The pattern determines its form.
V1 / base form
—
The base verb without to: work, go, be.
V3 / past participle
—
The third verb form: worked, gone, seen. Used after have/has or in the passive, for example; it is not always the same as V2.
clause
—
A construction with a verb, often with its own subject: when I arrived. A non-finite clause may leave the subject unspoken: to get home.

It would appear that the archive was moved without anyone noting it.

It would appear that the archive was moved without anyone noting it.

A cautious, formal inference.

The two samples appear to have been mixed up in transit.

The two samples appear to have been mixed up in transit.

Appear to have been mixed up uses a perfect passive infinitive to draw a conclusion about an earlier event, with an explicit subject.

It seems that the vote has been postponed.

It seems that the vote has been postponed.

A less formal alternative without would.

5. Evidence and conclusion: order and links

You can state the basis first, then the conclusion: evidence, so conclusion. So, therefore and hence introduce a result or conclusion. Since and as in their causal meanings introduce the basis. These links are not interchangeable while retaining the same order.

The order is not fixed. You can begin with the conclusion and then give the evidence: Someone must have been in — the kettle is still warm. This sounds like a claim followed by its justification. Both orders are grammatical.

For coherent writing, name specific evidence instead of vaguely saying that everything points to something. You can follow a conclusion with a consequence that follows from it: That would also explain…. If there are several pieces of evidence, summarise them before the marker.

The studio door is propped open, the kettle is warm and the sign-in sheet has gone. Someone has clearly been in recently.

The studio door is propped open, the kettle is warm and the sign-in sheet has gone. Someone has clearly been in recently.

Three pieces of evidence come first, followed by a conclusion marked with an adverb.

Someone must have been in the studio; the kettle is still warm.

Someone must have been in the studio; the kettle is still warm.

The conclusion comes first, with the evidence offered as its basis. This is also natural.

If so, that would explain why the sign-in sheet has gone.

If so, that would explain why the sign-in sheet has gone.

This states a consequence that follows from the inference already made.

6. Degrees of confidence and the boundaries of the topic

The markers differ roughly in strength. Must and evidently / clearly present a confident inference. It would appear that and seem to are cautious. Presumably marks an assumption. Might, may and could allow a possibility. This is not a rigid ladder: assumption and evidentness are different dimensions. Your choice nevertheless shows how strongly you stand behind the inference.

Markers can combine, but check their joint meaning. Must probably can sound cumbersome or less strong than expected from must, yet it is not universally ungrammatical or logically contradictory. One precise marker often gives a clearer formulation.

Directly seeing or hearing something belongs to the topic of perception; what someone has told you belongs to reporting. Modals of possibility are also studied separately. They appear here only to compare degrees of commitment.

The train must have been delayed; the whole board is red.

The train must have been delayed; the whole board is red.

A confident deduction with explicit evidence.

It would appear that the train was delayed.

It would appear that the train was delayed.

A cautious, formal inference.

The train might have been delayed.

The train might have been delayed.

Might leaves the delay as a possibility. The sentence does not reveal how much evidence exists; speakers may be cautious for various reasons.

7. Inference in speaking and writing

In conversation, an inference often prompts a response: the other person accepts it or counters it with evidence. To reject it, state a fact that rules out the proposed explanation: It can’t have been the cleaner — she was on leave all week.

In a report or analysis, marking uncertainty matters more than sounding confident. Present an unproven cause with it would appear that or seems to have so readers can recognise it as an interpretation.

Calibrate your confidence: use a strong marker for strong evidence and a cautious one for weak evidence. If unsure, add an explicit qualification such as though I may be wrong. Stating the evidence helps the listener assess the inference.

It can't have been the bridge; the road was open all night.

It can't have been the bridge; the road was open all night.

The speaker treats the open road as grounds for rejecting an explanation involving the bridge. Whether this evidence is decisive depends on the explanation under discussion.

Sales appear to have dipped after the redesign, though the figures are provisional.

Sales appear to have dipped after the redesign, though the figures are provisional.

A cautious marker in a written report.

The cables are unplugged, so someone must have moved the desk, though I may be wrong.

The cables are unplugged, so someone must have moved the desk, though I may be wrong.

An inference with an explicit qualification.

Common mistakes

Incorrect:The train must left already; the platform is empty.

Correct:The train must have left already; the platform is empty.

A bare infinitive follows must. For a past event, use the perfect infinitive have + past participle, not a past-tense form.

Incorrect:He must has forgotten the file.

Correct:He must have forgotten the file.

Use the base form have after must, not has. The degree of confidence in the inference is a separate issue from this grammatical form.

Incorrect:It would appear that the figures to be wrong.

Correct:It would appear that the figures are wrong.

It would appear that takes a complete subordinate clause with a finite verb, not an infinitive.

Incorrect:She seems to have went home early.

Correct:She seems to have gone home early.

Use the past participle gone after to have, not the past-tense form went.

Incorrect:It must have been rained last night.

Correct:It must have rained last night.

Rain is intransitive here and does not form a passive. Use rained directly after have.

Sources
Practise with Vocairo