Semantic Properties of the Subject

The subject is typically the theme (or topic) of the sentence. It usually refers to information that is regarded by the speaker as given. Hence, when it is expressed by a common noun, it generally combines with the definite article, e.g.:

The white hat is Mother's (V. Evans).

The subject performs a number of semantic roles in the sentence. With transitive action verbs, the subject often denotes an agent, i.e. the wilful initiator of the action, e.g.:

He closed the door... (H. Fielding).

The subject may also express the inanimate external causer of an event, e.g.:

A sudden gust of wind blew the door shut (Longman Dictionary of Contemporary English).

In other cases, the subject identifies the instrument or means used by an agent to perform an action, e.g.:

The key opened the door (ChJ. Fillmore).

Although the subject is often associated with agency, it may express a number of non-agentive roles. With very many stative verbs (denoting relationship and mental states of perception, cognition, and emotion), we find a recipient subject, e.g.:

/ could just hear the music in the distance (Oxford Collocations Dictionary).

Verbs denoting position in space combine with a positioner subject. The positioner role is particularly common with intransitive stance verbs, such as sit, stand, lie, live, stay, remain, etc. Cf: I have lived in London most of my life (R. Quirk et a].).

They are staying at a motel (R. Quirk et al.).

My friend is sitting in a chair near the door (R. Quirk et al.).

Other, less common semantic roles of the subject, are local and temporal. Cf:

Chicago is too windy (R. Quirk et al.).

Yesterday was sunny (R. Quirk et al.).

Local and temporal roles are generally expressed by adverbials and situational modifiers rather than the subject. Cf: It is too windy in Chicago (R. Quirk et al.). It was sunny yesterday (R. Quirk et al.).

Structural Types of Subjects

Structurally, subjects fall into four types: simple, complex, discrete, and clausal. A simple subject is expressed by a single notional word or a non-clausal combination of words. Cf.:

The police are close to solving the mystery of the missing murder weapon (Oxford Collocations Dictionary).

Air travel has lost much of its mystery (Oxford Collocations Dictionary).

A complex subject consists of two components linked by secondary predication, e.g.: They were seen taking the train to Paris (S. Sheldon), where the components they and taking are linked by secondary predication.

True, some linguists [for instance, V.L. Kaushanskaya and her co-authors; B.A. Hyish] regard the participle taking as part of a compound predicate, were seen taking the train. B.S. Khaimovich and B.I. Rogovskaya question the validity of such an approach on transformational grounds. The passive construction They were seen taking the train to Paris is generated from the active construction People saw them taking the train to Paris, in which the combination them taking the train is undoubtedly a complex object. And the object of an active construction corresponds to the subject of a parallel passive construction. Since them taking the train is a complex object in the active construction, in the passive construction it corresponds to the complex subject they ... taking the train.

THE PREDICATE