Verbs of this type have two core roles. A Perceiver (which is HUMAN or higher animate) finds out something about an Impression through use of eyes, or ears, or nose, or the taste-buds in the tongue, or the tactile feelings in the skin. The Perceiver is always mapped onto A and the Impression onto O syntactic relation. Most subtypes of ATTENTION are Primary-B, in that the Impression can be an NP or a complement clause; one subtype must have the Impression realized through an NP and is thus Primary-A.

People gather more kinds of information by their eyes than by other sense organs, and many ATTENTION verbs imply vision, e.g. see, watch, look (at), stare (at), peep (at), inspect. The only verbs specifically referring to audition are hear and listen (to). The other human senses are each represented by a single verb—feel, smell and taste (these are also classified as CORPOREAL). There are, however, a number of general verbs of ATTENTION which—while most frequently being used for something which is seen—can be used to refer to any of the senses, e.g. notice, recognize, study, as in I noticed, on tasting it, that he’d put in too much salt; She recognized John’s voice; He is studying the various smells produced in a Thai kitchen.

The subtypes that can be recognized are:

(a) The SEE subtype, involving straightforward description of an act of perception (which can be involuntary)—see, hear, smell, taste, feel. Also in this subtype are observe, which refers to seeing or hearing something happening; notice, seeing or hearing something which stands out from its background; and perceive, which implies picking out some particular thing or state or event from its background (and is also used as a high-flown alternative to other verbs from this subtype).

(b) The SHOW subtype, describing how one person assists another to an act of perception. The main verb in this subtype, show, is lexical causative of see/notice/observe. There will be a Causer in A slot, and either Perceiver or Impression will be in O relation, according to which is focused on in this instance, e.g. John picked up the book and showed it (Impression: O) to Mary (Perceiver), or John brought Mary over and showed her (Perceiver: O) the book (Impression).

When show has NPs realizing all roles it implies visual perception, e.g. John showed the parrot to Mary implies that she saw it, not that she heard it. But when the Impression is a complement clause, then show may imply use of the eyes—John showed Mary how to mend a fuse can imply that he did it, and she observed this—or of the ears—John showed Mary how to make a uvular trill implies that he made the sound, and she heard it. (Demonstrate is a near synonym of this sense of show.)

(c) The RECOGNIZE subtype, referring to perception of something (by any sense) and then knowing what it is, or what its significance is—recognize, spot.

(d) The DISCOVER subtype, referring to perception of something that was not previously apparent, e.g. discover ‘perceive something (which may be surprising) for the first time’; find ‘perceive something that was either looked for, or which is familiar from the past’.

(e) The WITNESS subtype, referring to observation of some definite unit of activity; witness may be the only member.

(f) The LOOK subtype, referring to the Perceiver directing their attention in order to connect with some Impression, e.g. look (at), listen (to) and the more specific verbs stare (at), glare (at), peep (at), peer (at), squint (at); eavesdrop (on); also search (for), look (for), hunt (for); inspect, study, investigate, scan, scrutinize, examine, check, view; explore, survey; visit (which involves intersection of MOTION and ATTENTION).

(g) The WATCH subtype, similar to (f) but referring to deliberate perception over a period of time. Watch may be the only verb uniquely belonging to this subtype; the contrast with look (at) can be seen in the acceptability of I watched John eat his dinner but not *I looked at John eat his dinner. Listen (to) has two senses, one parallel to look (at), belonging to subtype (f) (cf. Look at this picture!, Listen to this noise behind the skirting!), and the other parallel to watch, in subtype (g), e.g. I listened to John say his prayers.

The subtypes have differing grammatical properties:

(i) Omission of object NP

All ATTENTION verbs are basically transitive. Some involve an inherent preposition but the following NP has the same syntactic properties as for those items where it immediately follows the verb root—compare The repairman hasn’t yet looked at our washing-machine and The foreman hasn’t yet inspected that new switchboard, and their passives, Our washing-machine hasn’t yet been looked at, and That new switchboard hasn’t yet been inspected.

An O NP, coding the Impression role, may be omitted after verbs in the LOOK and WATCH subtypes (a preceding preposition will then also drop). A sentence such as He is listening/ looking/ staring/ hunting/ checking/ exploring/ watching simply focuses on the way in which the Perceiver is directing their attention, without noting any specific Impression to which it may be directed.

LOOK verbs, especially when the O NP is omitted, may take a spatial adverbial which is semantically linked to the verb, and thus must come after the predicate, e.g. He is exploring to the north, She is hunting in the forest. An O NP could always be included, e.g. He is exploring the country to the north, She is hunting (for) rabbits in the forest.

Look (at) and look (for) are distinct lexemes—compare She is looking at a millionaire and She is looking for a millionaire. This contrast is neutralized when the O NPs (and preceding prepositions) are dropped, e.g. She is looking under the table. But, once again, an O NP could always be stated, e.g. She is looking at the hole in the carpet under the table, or She is looking for spilt peanuts under the table (in each sentence, the two prepositional NPs could occur in either order).

For three verbs in the SEE subtype—see, hear and notice—an O NP can be omitted if it could be inferred from the preceding discourse or context, e.g. ‘Mary hit John on the temple!’ ‘Yes, I saw’ (sc. the blow), or ‘John gave his pudding to the dog!’ ‘Yes, I noticed’ (sc. John(’s) giving his pudding to the dog). An O NP cannot be omitted after observe or perceive; here one must include at least it, e.g. ‘Did you know there was an eclipse of the sun today?’ ‘Yes, I observed it’. Smell, taste and feel, in the senses corresponding to subtype (a), also require an O NP to be stated. These verbs are used less frequently than see, hear and notice, which may be why no convention for omitting an it NP has yet evolved.

Show, of subtype (b), must include either Perceiver or Impression in O slot, e.g. Mary showed John her ring or Mary showed her ring to John. It can freely omit a non-O Perceiver, e.g. John and Mary showed their wedding presents (to the guests). And show can omit a non-O Impression NP where this is inferable from previous discourse, e.g. ‘Does Mary know where the key is?’ ‘She should, I showed her.’

(ii) Realization of Impression role

All ATTENTION verbs can have a CONCRETE NP realizing Impression, except for witness, which must relate to an activity, e.g. He witnessed the battle, She witnessed John’s signature on the document (note that signature is an ACTIVITY noun—a paraphrase would be She witnessed John’s signing his name on the document). All ATTENTION verbs can have an ACTIVITY noun as Impression (e.g. They noticed/discovered/viewed the football match) except perhaps explore and survey, which in their central meanings relate to some geographical feature.

Most verbs in the LOOK subtype may only take an NP in O slot (and are thus Primary-A); some LOOK verbs can take a WH-clause, e.g. examine, investigate, study. All other subtypes allow complement clauses for the Impression role. We now discuss the various kinds of complement one at a time.

(iii) THAT and WH- complements

These two varieties of complement clause can fill the O slot for subtypes (a)–(e) and (g). Thus, I noticed/smelt/recognized/discovered that the meat was off/where the cheese was hidden. A THAT clause with see can refer to an inference from direct observation (I saw that his leg was broken) or to a general mental assessment (I saw that it was pointless to continue). Feel has similar properties, e.g. I felt that the dough was sufficiently kneaded (tactile observation) and I felt that she was the right person for the job (intuition). A THAT clause with hear almost always refers to something the Perceiver has been told, e.g. I heard that John had cursed; for reporting direct observation a different variety of complement would be preferred, e.g. I heard John curse, I heard John(’s) cursing.

Subtype (g), with watch and one sense of listen (to), may take THAT and WH- clauses which directly describe some activity, e.g. I watched that he crossed the road safely, and She listened whether he locked all the doors before going to bed.

(iv) TO complements

A smallish number of ATTENTION verbs may take a special variety of Modal (FOR) TO complement clause: the to is obligatorily omitted in an active construction, but obligatorily included in the passive, e.g. Everyone saw John kick Mary, John was seen to kick Mary.

It is important to distinguish this TO complement construction, with the to omitted, from a THAT complement clause, which can omit the that when it comes directly after the predicate, e.g. I noticed (that) John kicked Mary (every time he went past)—here the verb kicked shows tense inflection, indicating that it is in a THAT clause—and I noticed John kick Mary (when no one was looking)—here the verb is in base form, as it always is in a TO clause. (For a verb like hit, which makes no distinction between the base and past tense forms, these would fall together, i.e. I noticed John hit Mary is ambiguous between THAT and TO readings.)

This variety of TO complement, where to is omitted in the active, occurs with see, hear and notice and, less readily, with feel, smell, observe and perceive from the SEE subtype (but not with taste). It is also attested with subtype (g), WATCH, but only in the active, e.g. I watched John hit Mary, I listened to him sing (here to comes from listen to, rather than being the complementizer); there are no acceptable passives of these sentences. (Van Ek (1966: 68) also mentions examples with find, from subtype (d), but these seem somewhat archaic; Bolinger (1974) quotes examples with show and look at, e.g. Can you show it happen? and Look at him run! The look example is only possible in the active.)

In addition, verbs in subtypes (a)–(d) may take a Judgement TO complement clause. Judgement TO clauses most frequently have their VP beginning with be (although other possibilities do occur, e.g. I noticed John to have lost some weight since last Christmas). When be is the copula, then to be can be omitted only after verbs of the DISCOVER subtype, e.g. I found John (to be) dead, but We noticed John to be dead, where the to be must be retained. When be is the imperfective auxiliary, to be may be omitted after verbs from DISCOVER, SEE or SHOW, e.g. I noticed/discovered John (to be) singing a hymn.

(v) ING complement

This occurs with verbs from the SEE, SHOW, WITNESS and WATCH subtypes, e.g. We observed/ watched/ witnessed John(’s)stealing those apples; I can’t hear John(’s) playing the trumpet. The subject of the complement clause can take possessive marking, but this is most frequently omitted. (ATTENTION verbs seem particularly prone to loss of a complementizer; we just described a type of TO clause where to must be omitted in the active.)

A construction like John noticed that tall man watching Mary, with the complement clause subject followed by a verb in -ing form, can be derived in two ways: by omission of possessive marker from the subject of an ING clause, or by omission of to be from a Judgement TO complement whose VP begins with the imperfective auxiliary be. With some verbs there is no problem of ambiguity. Watch and witness may only take an ING, not a Judgement TO clause, and so I watched/witnessed that tall man(’s) saying his prayers in church (from two until four, so he couldn’t have committed the burglary which took place at three o’clock) must be an ING complement, describing some durative event. Similarly, discover only takes a TO, not an ING, complement, and so I discovered that tall man (to be) saying his prayers (just when I’d decided he must be an atheist) is also unambiguous, referring to the perception of some fact that was not previously known. But verbs from the SEE and SHOW subtypes can take both ING and TO complement clauses; an abbreviated sentence such as I noticed that tall man saying his prayers is thus ambiguous between the readings of the watch/witness and of the discover sentences just given.

There is still further room for ambiguity. In the discussion of relative clauses, we mentioned a reduced form of restrictive relative clause referring to present time which, for verbs that take the be . . . -ing auxiliary, effectively involves omission of the relative pronoun and the form of be. Thus I noticed that tall man (who was) watching Mary (he looks just like the picture on the ‘Wanted’ poster), where (who was) watching Mary helps restrict the reference of the O NP. This has a quite different meaning from the ING complement construction I noticed that tall man(’s) watching Mary (all afternoon, and took great offence at his ogling my wife for such a long time), where what I noticed was not the identity of the tall man, but the fact of his watching Mary. The abbreviated sentence I noticed that tall man watching Mary would thus be ambiguous between these two readings.

Complement clauses with ATTENTION verbs have one special property. The complement clause subject is generally distinct from the main clause subject, for the straightforward reason that one would not normally see or hear etc. oneself (or, perhaps more to the point, one would not normally report doing so). It is possible for the two subjects to have the same reference, but under no circumstances can the complement clause subject be omitted, e.g. myself cannot be dropped from I saw myself on the video, I finally recognized myself to be middle-aged. This contrasts with verbs from a number of other subtypes, where coreferential omission is normal, e.g. I want (?myself/me) to eat an avocado.

There are three further sets of ATTENTION verbs:

(i) Ignore, disregard, overlook, pass NP over refer to the Perceiver not making contact with a certain Impression (either accidentally or on

purpose). These verbs are transitive, with either an NP or an ING complement clause in O slot, e.g. She walked by and ignored me/ignored my waving at her.

(ii) Appear, disappear are intransitive and refer to an Impression (in S relation) being available or not available for the visual attention of a potential Perceiver. A Perceiver can be included with appear, marked by preposition to, e.g. An angel appeared to Mary. (With disappear we can say The angel disappeared from the scene/from (Mary’s) view, but not *The angel disappeared from Mary.) Appear is also a member of the SEEM type.

(iii) Look, sound, smell, taste and feel are also intransitive verbs, with the Impression in S slot; the Perceiver may be included, marked by to, e.g. This violin sounds good (to me) (now that it has been tuned), That chicken tasted really lovely (to all of us). Note that there is one verb in this set corresponding to each of the five senses. Smell, taste and feel are identical in form to the corresponding transitive verb, e.g. She felt the fur (transitive), It felt soft and silky (to her) (intransitive). Intransitive look corresponds to transitive see and look (at), e.g. He saw/looked at the painting and The painting looks good. Only sound (derived from the noun) is not cognate with a corresponding transitive verb from the ATTENTION type. (There is of course a transitive verb sound with a meaning entirely different from hear and listen (to), and with quite restricted use, e.g. sound the trumpet ‘make it sound out’.)

Both semantically and syntactically these five verbs behave like the SEEM type; they involve an intersection of this type with ATTENTION (and, for smell, taste and feel, also with CORPOREAL). They are normally followed by an adjective from the VALUE, DIFFICULTY or QUALIFICATION types, or the CLEVER subtype of HUMAN PROPENSITY, e.g. It looks difficult, It sounds definite. Interestingly, bad can be omitted after smell, i.e. It smells implies It smells bad. (Note that the derived adjective smelly refers to ‘a bad smell’ while tasty means ‘a good taste’. One might expect, on a principle of analogy, that good should be omissible from It tastes good. It is not; languages seldom work on so symmetrical a pattern as this.)