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.
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.
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.