English clause syntax

This article describes the syntax of clauses in the English language, chiefly in Modern English. A clause is often said to be the smallest grammatical unit that can express a complete proposition. But this semantic idea of a clause leaves out much of English clause syntax. For example, clauses can be questions, but questions are not propositions. A syntactic description of an English clause is that it is a subject and a verb. But this too fails, as a clause need not have a subject, as with the imperative, and, in many theories, an English clause may be verbless. The clause in English cannot, therefore, be described by necessary and sufficient conditions. The idea of what qualifies varies between theories and has changed over time.

History of the concept

The earliest use of the word clause in Middle English is non-technial and similar to the current everyday meaning of phrase: "A sentence or clause, a brief statement, a short passage, a short text or quotation; in a ~, briefly, in short; (b) a written message or letter; a story; a long passage in an author's source."

The first English grammar, Pamphlet for Grammar by William Bullokar, was published in 1586 and briefly mentions clause once, without explaining the concept.

A technical meaning is evident from at least 1865, when Walter Scott Dalgleish describe a clause as "a term of a sentence containing a predicate within itself; as... a man who is wise."

In the early days of generative grammar, new conceptions of the clause were emerging. Paul Postal and Noam Chomsky argued that every verb phrase had a subject, even if none was expressed, (though Joan Bresnan and Michael Brame disagreed). As a result, every verb phrase (VP) was thought to head a clause.

The idea of verbless clauses was perhaps introduced by James McCawley in the early 1980s with examples like the underlined part of with John in jail... meaning "John is in jail".

Types of clause in Modern English

Clauses can be classified as independent (main clauses) and dependent (subordinate clauses). An orthogonal way of classifying clauses is by the speech act they are typically associated with. This results in declarative (making a statement), interrogative (asking a question), exclamatory sentence, and imperative (giving an order), each with its distinctive syntactic features. Declarative and interrogative clauses may be independent or dependent, but imperative clauses are only independent.

Dependent clauses have other cross-cutting types. These include relative and comparative clauses; and participial and infinitival clauses.

Finally, there are verbless clauses.

Examples

English Clause types

	Independent	Dependent (underlined)
Declarative	This is a tree.	I think (that) this is a tree.
Interrogative	Is this a tree? What is this?	I wonder whether / if this is a tree. I wonder what this is.
Imperative	Be still. Stop.
Relative		This is the tree (that) I saw. The tree is in my yard, where I planted it. The this is a tree to behold.
Comparative		This tree is taller than that one is.
Infinitival		I can see it. I want to see it.
Participial		I'm looking at the tree. I'm shaded by the tree.
Verbless	What a great thing to do! How odd that nobody noticed! Out of my way!	He stood there quiety, his hands in his pockets. Whether a fact or not, it is commonly believed. Whatever the reason, it's annoying. He didn't love her as much as she him. The bramble shook as if alive.

Independent clause types

Declarative

By far, the most comon type of English clause is the independent declarative. The typical form of such clauses consist of two constituents, a subject and a head verb phrase (VP) in that order, with the subject corresponding to the predicand and the head VP corresponding to the predicate. For example, the clause Jo did it has the subject noun phrase Jo followed by the head VP did it. Declarative clauses are associated witht the speech act of making a statement.

Information packaging constructions can result in the addition of other constituents and various constituent orders. For example, the it-cleft construction has it as a dummy subject, followed by a head VP containing a form of the verb be + a complement corresponding to the predicand + a relative clause whose head corresponds to the predicate. So, the example above as an it-cleft is It was Jo who did it.

V2

Some declarative clauses follow V2 order, which is to say the first verb appears as the second constituent, even if the subject is not the first constituent. An example would be Never did I say such a thing, where never is the first constituent and did is the verb in V2 position.

Interrogative

There are two main types of independent interrogative clauses: open and closed. These are most associated with asking questions, but they can be used for other speech acts such as giving advice, making requests, etc.

Open interrogatives include an interrogative word, which, in most cases either is the subject (e.g., Who went to the shop?) or comes before an auxiliary verb + the subject. This is seen in What did you buy there? where what is the interrogative word, did is the auxliary, and you is the subject. In such cases, the interrogative word is said to be fronted, or it may be part of a fronted consitutent, as in which shop did you go to? It can also appear in the non fronted position, so that the example above could be You bought what there? where what is an object in the VP. When it is fronted, many modern theories of grammar posit a gap in the non-fronted position: What did you buy __ there?

Closed interrogative clauses can be further subdivided as polar or alternative. A polar interrogative is one to which the expected response is yes or no. For example, Do you like sweets? is a polar interrogative. An alternative interrogative is one asking for a choice among two or more alternatives, as in Would you like coffee or tea? In both types of closed interrogatives, an auxiliary verb is fronted. That is to say, it comes before the subject. In the example above, would is the fronted auxiliary verb and you is the subject.

Imperative

In most imperative clauses the subject is absent: Eat your dinner! However imperative clauses may include the subject for emphasis: You eat your dinner!. The form of the verb is the base form of the verb, such as eat, write, be. Modal verbs do not have imperative forms. Negation uses do-support, even if the verb is be; see § Negation below. The imperative here refers to second-person forms; constructions for other persons may be formed periphrastically, e.g. Let's (let us) go; Let them eat cake.

Dependent clause types

A dependent clause may be finite (based on a finite verb, as independent clauses are), or non-finite (based on a verb in the form of an infinitive or participle). Particular types of dependent clause include relative clauses, content clauses and adverbial clauses.

In certain instances, clauses use a verb conjugated in the subjunctive mood; see English subjunctive.

Clauses can be nested within each other, sometimes up to several levels. For example, the sentence I know the woman who says she saw your son drinking beer contains a non-finite clause (drinking beer) within a content clause (she saw your son drinking beer) within a relative clause (who says she saw your son drinking beer) within an independent declarative clause (the whole sentence).

Non-finite clauses

A non-finite clause is one in which the main verb is in a non-finite form, namely an infinitive, past participle, or -ing form (present participle or gerund); for how these forms are made, see English verbs. (Such a clause may also be referred to as an infinitive phrase, participial phrase, etc.)

The internal syntax of a non-finite clause is generally similar to that of a finite clause, except that there is usually no subject (and in some cases a missing complement; see below). The following types exist:

• bare infinitive clause, such as go to the party in the sentence let her go to the party.
• to-infinitive clause, such as to go to the party. Although there is no subject in such a clause, the performer of the action can (in some contexts) be expressed with a preceding prepositional phrase using for: It would be a good idea for her to go to the party. The possibility of placing adjuncts between the to and the verb in such constructions has been the subject of dispute among prescriptive grammarians; see split infinitive.
• past participial clause (active type), such as made a cake and seen to it. This is used in forming perfect constructions (see below), as in he has made a cake; I had seen to it.
• present participial clause, such as being in good health. When such a clause is used as an adjunct to a main clause, its subject is understood to be the same as that of the main clause; when this is not the case, a subject can be included in the participial clause: The king being in good health, his physician was able to take a few days' rest.
• gerund clause. This has the same form as the above, but serves as a noun rather than an adjective or adverb. The pre-appending of a subject in this case (as in I don't like you drinking, rather than the arguably more correct ...your drinking) is criticized by some prescriptive grammarians – see Fused participle.

In certain uses, a non-finite clause contains a missing (zero) item – this may be an object or complement of the verb, or the complement of a preposition within the clause (leaving the preposition "stranded"). Examples of uses of such "passive" non-finite clauses are given below:

• to-infinitive clauses – this is easy to use (zero object of use); he is the man to talk to (zero complement of preposition to).
• past participial clauses – as used in forming passive voice constructions (the cake was made, with zero object of made), and in some other uses, such as I want to get it seen to (zero complement of to). In many such cases the performer of the action can be expressed using a prepositional phrase with by, as in the cake was made by Alan.
• gerund clauses – particularly after want and need, as in Your car wants/needs cleaning (zero object of cleaning), and You want/need your head seeing to (zero complement of to).

For details of the uses of such clauses, see § Uses of non-finite constructions below. See also English passive voice (particularly under Additional passive constructions).

Verbless clauses

Further information: Verbless clause

Verbless clauses are comprised of a predicand and a verbless predicate. For example, the underlined string in [With the children so sick,] we've been at home a lot means the same thing as the clause the children are so sick. It attributes the predicate "so sick" to the predicand "the children". In most contexts, *the children so sick would be ungrammatical. Verbless clauses of this sort are common as the complement of with or without.

Other prepositions such as although, once, when, and while also take verbless clause complements, such as Although no longer a student, she still dreamed of the school, in which the predicand corresponds to the subject of the main clause, she. Supplements, too can be verbless clauses, as in Many people came, some of them children or Break over, they returned to work.

Neither A comprehensive grammar of the English language norThe Cambridge grammar of the English language offer any speculations about the structure(s) of such clauses. The latter says, without hedging, "the head of a clause (the predicate) is realised by a VP." It's not clear how such a statement could be compatible with the existence of verbless clauses.

Constituents of a clause

English is an SVO language, that is, in simple declarative sentences the order of the main components is subject–verb–object(s) (or subject–verb–complement).

A typical finite clause consists of a noun phrase functioning as the subject, a finite verb, followed by any number of dependents of the verb. In some theories of grammar the verb and its dependents are taken to be a single component called a verb phrase or the predicate of the clause; thus the clause can be said to consist of subject plus predicate.

Dependents include any number of complements (especially a noun phrase functioning as the object), and other modifiers of the verb. Noun phrase constituents which are personal pronouns or (in formal registers) the pronoun who(m) are marked for case, but otherwise it is word order alone that indicates which noun phrase is the subject and which the object.

The presence of complements depends on the pattern followed by the verb (for example, whether it is a transitive verb, i.e. one taking a direct object). A given verb may allow a number of possible patterns (for example, the verb write may be either transitive, as in He writes letters, or intransitive, as in He writes often).

Some verbs can take two objects: an indirect object and a direct object. An indirect object precedes a direct one, as in He gave the dog a bone (where the dog is the indirect object and a bone the direct object). However the indirect object may also be replaced with a prepositional phrase, usually with the preposition to or for, as in He gave a bone to the dog. (The latter method is particularly common when the direct object is a personal pronoun and the indirect object is a stronger noun phrase: He gave it to the dog would be used rather than ?He gave the dog it.)

Adverbial adjuncts are often placed after the verb and object, as in I met John yesterday. However other positions in the sentence are also possible; see English grammar § Adverbs, and for "phrasal" particles, Phrasal verb. Another adverb which is subject to special rules is the negating word not; see § Negation below.

Objects normally precede other complements, as in I told him to fetch it (where him is the object, and the infinitive phrase to fetch it is a further complement). Other possible complements include prepositional phrases, such as for Jim in the clause They waited for Jim; predicative expressions, such as red in The ball is red; subordinate clauses, which may be introduced by a subordinating conjunction such as if, when, because, that, for example the that-clause in I suggest that you wait for her; and non-finite clauses, such as eating jelly in the sentence I like eating jelly.

Many English verbs are used together with a particle (such as in or away) and with preposition phrases in constructions that are commonly referred to as "phrasal verbs". These complements often modify the meaning of the verb in an unpredictable way, and a verb-particle combination such as give up can be considered a single lexical item. The position of such particles in the clause is subject to different rules from other adverbs; for details see Phrasal verb.

English is not a "pro-drop" (specifically, null-subject) language – that is, unlike some languages, English requires that the subject of a clause always be expressed explicitly, even if it can be deduced from the form of the verb and the context, and even if it has no meaningful referent, as in the sentence It is raining, where the subject it is a dummy pronoun. Imperative and non-finite clauses are exceptions, in that they usually do not have a subject expressed.

Adjuncts are constituents which are not required by the main verb, and can be removed without leaving behind something ungrammatical. Adjuncts are usually adverbs or adverbial phrases or clauses.

Many clauses have as their finite verb an auxiliary, which governs a non-finite form of a lexical (or other auxiliary) verb. For clauses of this type, see § Clauses with auxiliary verbs below.

Variations on SVO pattern

Variations on the basic SVO pattern occur in certain types of clause. The subject is absent in most imperative clauses and most non-finite clauses (see the {{Section link}}: required section parameter(s) missing and § Non-finite clauses sections). For cases in which the verb or a verb complement is omitted, see § Elliptical clauses.

The verb and subject are inverted in most interrogative clauses. This requires that the verb be an auxiliary or copula (and do-support is used to provide an auxiliary if there is otherwise no invertible verb). The same type of inversion occurs in certain other types of clause, particularly main clauses beginning with an adjunct having negative force (Never have I witnessed such carnage), and some dependent clauses expressing a condition (Should you decide to come,...). For details see subject–auxiliary inversion and negative inversion.

A somewhat different type of inversion may involve a wider set of verbs (as in After the sun comes the rain); see subject–verb inversion.

In certain types of clause an object or other complement becomes zero or is brought to the front of the clause: see § Fronting and zeroing.

Clauses with auxiliary verbs

In many English clauses, the finite verb is an auxiliary verb, whose complement is some type of non-finite clause. For example, in the clause he is eating his dinner, the finite verb is the auxiliary is, whose complement is the participial clause eating his dinner. In some cases the non-finite clause itself has an auxiliary as its main verb, with another embedded non-finite clause as complement. For example:

• He has (been (eating his dinner)).

Here eating his dinner is the complement of been, and been eating his dinner is the complement of has.

The form of each lexical or auxiliary verb (apart from the first) is determined by the auxiliary preceding it. The first auxiliary is conjugated as a finite verb in present or past tense: the modals are invariant, but the other auxiliaries may take the forms have, has, had, am, is, are, be (subjunctive), was, were, do, does, did. (If the clause being considered is a non-finite clause, then the initial auxiliary form may be having, (to) have, being, or (to) be.)

The principal auxiliaries and the verb forms they govern are:

• Modal verbs (will, can, could, etc.). They govern a bare infinitive (or to-infinitive in the case of ought and used).
• The verb have (and its inflected forms) to express perfect aspect. These govern a past participle (with an active meaning).
• The verb be (and inflected forms) to express progressive aspect. These govern a present participle.
• The verb be (and inflected forms) to express passive voice. These govern a past participle (used passively, i.e. with a zero object or preposition complement).
• The verb do (and inflected forms) to supply an auxiliary in functions where one is required, or to provide emphasis. This is described in more detail in the article on do-support.

A modal verb, if present, comes first. Any other auxiliaries come in the order listed above, namely perfect have followed by progressive be followed by passive be. The auxiliary do is not used in combination with any other auxiliary. Otherwise, the above auxiliaries can be used in any combination (but with no more than one instance from each group).

A clause containing the maximum number of auxiliaries might therefore be I will have been being operated on for six hours. Here the modal will is the finite verb; perfect have is in bare infinitive form (since it follows a modal), progressive be is in the past participle form been (following perfect have), passive be is in the present participle form being (following progressive be), and the lexical verb is in the past participle form operated (following passive be; here it is the dependent preposition on that has zero complement).

Constructions of this type serve a variety of functions, including the expression of aspect, voice and modality. The meaning of combinations of these auxiliary verbs are presented in more detail later in this article.

Some of these constructions are described, particularly in teaching contexts, as tenses – for example, is eating is represented as the "present progressive tense" of eat. (This terminology is rejected by many theoretical grammarians, since the construction does not serve purely to indicate present time, but also encodes aspectual information.) The series of auxiliaries and non-finite verb form is treated as a unit. Thus in the examples above, the strings is eating and has been eating may be presented as forms of the verb eat, with his dinner serving as their object. (From a theoretical perspective, these verb series are examples of catenae.)

Non-finite constructions exist for combinations of auxiliary verbs other than the modals verbs or do:

• infinitive: (to) take, (to) be taken, (to) be taking, (to) have been taking, etc.
• present participial (or gerund): taking, being taken, having taken, etc. (but not normally in the progressive cases)

The verbs ought and used differ from other modals in that they require the to-infinitive rather than the bare infinitive: He ought to go; We used to go (for this reason they are not always classified as modals). There are certain other auxiliary-like expressions that are variously classified:

• (be) going to
• have to
• am to, was to, etc.
• (be) able to
• (be) about to

Fronting and zeroing

In interrogative and relative clauses, wh-fronting occurs; that is, the interrogative word or relative pronoun (or in some cases a phrase containing it) is brought to the front of the clause: What did you see? (the interrogative word what comes first even though it is the object); The man to whom you gave the book... (the phrase to whom, containing the relative pronoun, comes to the front of the relative clause; for more detail on relative clauses see English relative clauses).

Fronting of various elements can also occur for reasons of focus; occasionally even an object or other verbal complement can be fronted rather than appear in its usual position after the verb, as in I met Tom yesterday, but Jane I haven't seen for ages. (For cases in which fronting is accompanied by inversion of subject and verb, see negative inversion and subject–verb inversion.)

In certain types of non-finite clause ("passive" types; see non-finite clauses above), and in some relative clauses, an object or a preposition complement is absent (becomes zero). For example, in I like the cake you made, the words you made form a reduced relative clause in which the verb made has zero object. This can produce preposition stranding (as can wh-fronting): I like the song you were listening to; Which chair did you sit on?

Negation

A clause is negated by the inclusion of the word not:

• In a finite indicative clause in which the finite verb is an auxiliary or copula, the word not comes after that verb, often forming a contraction in n't: He will not (won't) win.
• In a finite indicative clause in which there is otherwise no auxiliary or copula, do-support is used to provide one: He does not (doesn't) want to win.
• In the above clause types, if there is inversion (for example, because the sentence is interrogative), the subject may come after the verb and before not, or after the contraction in n't: Do you not (Don't you) want to win? (In the case of inversion expressing a condition, the contracted form is not possible: Should you not (not: *Shouldn't you) wish to attend...
• Negative imperatives are formed with do-support, even in the case of the copula: Don't be silly!
• The negative of the present subjunctive is made by placing not before the verb: ...that you not meet us; ...that he not be punished. The past subjunctive were is negated like the indicative (were not, weren't).
• A non-finite clause is negated by placing not before the verb form: not to be outdone (sometimes not is placed after to in such clauses, though often frowned upon as a split infinitive), not knowing what to do.

Elliptical clauses

Certain clauses display ellipsis, where some component is omitted, usually by way of avoidance of repetition. Examples include:

• omitted verb between subject and complement, as in You love me, and I you (where the same verb love is understood between I' and you).
• tag questions, as in He can't speak French, can he? (where the infinitive clause speak French is understood to be the dependent of can).
• similar short sentences or clauses such as I can, there is, we will, etc., where the omitted non-finite clause or other complement is understood from what has gone before (for examples involving inversion, such as so/neither do I, see subject–auxiliary inversion).

For more analysis and further examples, see Verb phrase ellipsis.

Uses of non-finite constructions

The various types of non-finite clauses described above have a number of uses besides the constructions with auxiliaries already described.

Infinitive

An infinitive phrase begins with the base form of the verb. Infinitive phrases can be viewed as part of finite clauses where they are introduced in verb catenae by an auxiliary verb or by a certain limited class of main verbs. They are also often frequently introduced by a main verb followed by the particle to. Further, infinitives introduced by to can function as noun phrases, or even as modifiers of nouns. The following table illustrates these environments:

Infinitive	Introduced by a (modal) auxiliary verb	Introduced by a main verb	Introduced by a main verb plus to	Functioning as noun phrase	Functioning as the modifier of a noun
laugh	Do not laugh!	That made me laugh.	I tried not to laugh.	To laugh would have been unwise.	the reason to laugh
leave	They may leave.	We let them leave.	They refused to leave.	To leave was not an option.	the thing to leave behind
expand	You should expand the explanation.	We had them expand the explanation.	We hope to expand the explanation.	To expand the explanation would have been folly.	the effort to expand

An infinitive phrase begins with the bare form of the first verb, and is usually co-ordinated by the word "to":

• I need to get my work done
• For them to be with us in this time of crisis is evidence of their friendship.

When the semantic agent of the verb phrase occurs as the object in the co-ordinating clause, "to" does not occur:

• I heard them shout.

Infinitive phrases are used after particular verbs such as "want" or "need".

The placement of an adverbial modifier directly after the to of an infinitive phrase (to slowly drift away) is called a split infinitive, and is sometimes regarded as a grammatical or stylistic error.

Present participle and gerund

A present participle phrase uses the present participle form of the verb, ending in "-ing".

It may be used in progressive constructions:

Infinitive	Progressive active participle
fix	The guy is fixing my bike.
open	the flower opening up
support	the news supporting the point
drive	She is driving our car.

The present participle may be used in non-finite constructions such as the following:

• Having spoken, he turned and left.
• Looking out the window, he saw a car go by.
• Having been beaten at poker, he had little money left.
• I saw them digging a hole.

The present participle form of a verb may function as a noun, in which case it is referred to as a gerund. Gerunds typically appear as subject or object noun phrases, or even as the object of a preposition:

Infinitive	Gerund as subject	Gerund as object	Gerund as object of a preposition
solve	Solving problems is satisfying.	I like solving problems.	No one is better at solving problems.
jog	Jogging is boring.	He has started jogging.	Before jogging, she stretches.
eat	Eating too much made me sick.	She avoids eating too much.	That prevents you from eating too much.
investigate	Investigating the facts won't hurt.	We tried investigating the facts.	After investigating the facts, we made a decision.

Often distinguishing between a gerund and a progressive active participle is not easy; the line between the two non-finite verb forms is not clear.

A present participle may function as an adjective modifying a noun, in which case it is known as a gerundive: "The dancing girls".

Past participle

The past participles of strong verbs in Germanic languages are irregular (e.g. driven); their form is idiosyncratic. The past participles of weak verbs, in contrast, are regular; their form is formed with the suffix -ed (e.g. fixed, supported, opened).

Past participles are used in perfect and passive constructions:

Infinitive	Perfect active participle	Passive participle
fix	He has fixed my bike	My bike was fixed.
open	The flower has opened up.	The flower has been opened up.
support	The news has supported the point.	the point supported by the news
drive	She has driven our car.	Our car should be driven often.

Past participles occur in a rare construction in English which may be compared with the ablative absolute construction in Latin:

• With these words spoken, he turned and left.

As with present participles, past participles may function as adjectives: "the burnt logs".