The syntactic status of principal and subordinate clauses as the predicative units of complex sentence

Complex sentence consists of two (or more) clauses that constitute an asymmetrical relationship: a subordinate clause and a matrix clause do not have equal status and equal function. A dependent clause may be subordinated to the principal clause or to another subordinate clause. Accordingly, subordinate clauses of the first, second, third degrees of subordination are distinguished [12].

Regarding the way in which the subordinate clauses relate to the principal one or to another subordinate clause, it should be pointed out that they are:

1) syntactically embedded;

2) formally marked as a dependent clauses;

3) integrated in a superordinate semantical structure;

4) part of the same processing and planning unit as the associated matrix clause [26].

Let's analyze each of these features.

1. Embedding is thought to be one of the most distinctive features that define subordinate constructions. From a syntactical point of view, each subordinate clause type plays a role of a particular sentence part within the principal clause or relates to it as a whole:

A type of subordinate clause	A sentence part of independent clause it represents
complement clause	subject or object
relative clause	attribute
adverbial clause	* pertains to the principal clause as a whole

 

This may be evidenced by substitution test, which shows that all three types of subordinate clauses can be paraphrased by nonclausal expressions:

I expect that he will apologize. (complement clause) → I expect his apologies.

We want to help children who were abused. (relative clause) →We want to help abused children.

She got married after her mother died. (adverbial clause) →She got married after her mother's death.

However, it is argued by Matthiessen and Thompson, that the substitution of adverbial clauses is highly controversial. By this reason it was suggested by Halliday, that adverbial clauses cannot be considered as embedded into the principal clause. It is our belief, though, that while some of the adverbial clauses are indeed loosely connected to a principal sentence, the others retain quite a strong connection to the matrix clause, therefore, should be considered syntactically embedded.

2. Subordinate clauses possess some formal properties that suggest their dependable position. That is, they are formally incomplete in isolation and can't stand on their own. They cannot constitute a complete utterance without the associated matrix clause [26]. For example, a nonfinite adverbial clause “W hile interrogating the witnesses ” couldn't possibly stand isolated from its principal counterpart “t he detective uncovered a lot of important details”.

Complementizers, or subordinate conjunctions also serve as a marker of dependency: They couldn't understand what was going on.

However, some of the finite complement clauses can, in fact, function independently, if not being introduced by connective words, as in: I think you should consider this offer.

3. Semantical characteristics also set subordinate clauses apart. According to Tomlin [26], they can be analyzed in terms of foreground and background information. Foreground is thought to pertain the central piece of information that contributes to the actual storyline. Background information, on the other hand, provides supportive material that elaborates the main events but does not narrate the story by itself. It is generally believed, that the principal clause encodes foreground information, while the dependent clause provides background information that supports or comments on it, for example: “ He yelled while he was in pain”. Switching the clauses as in “ He was in pain while he yelled ” disrupts the semantical integrity of the sentence. However, in some cases, this does not make any difference because the actions so closely coincide with each other it's hard to determine which one serves as a foreground and which – as a background. Compare: “ He was eating while he was watching TV ” and “ He was watching TV while he was eating”.

4. Within the paradigm ofdiscourse-oriented approach Langacker defined subordinate clauses as structures ‘whose profile is over-ridden by that of the matrix clause’ [26]. He argued that the matrix clause constitutes the ‘focal point’ of a complex sentence and can therefore be viewed as its ‘profile determinant’. That's why the semantic properties of the principal clause override that of the subordinate. For example, the sentence “ I can smell that the granny is backing cookies ” designates the process of smelling, not backing.

However, we must admit, that despite the seeming verisimilitude of Langacker's views, language practice suggests, that although he principal clause dominates the subordinate clause positionally, it doesn't necessarily mean that it expresses the central informative part of the sentence. The order of clauses plays a crucial role in distributing primary and secondary information among them. In unemphatic speech the main clause is often reduced to a mere introducer of the dependent clause, the latter part being more informative: I think, we should get cracking, buddy.

The principal clause often plays phatic function, that is, it's being used for the sole purpose of keeping up the conversation, as in: I'т sure we'll catch up later.