Subordinate clauses of secondary nominal positions include attributive clauses of various syntactic functions. They fall into two major classes: descriptive and restrictive, limiting attributive clauses. The descriptive attributive clause exposes some characteristic of the substantive referent as such, while the restrictive attributive clause performs a purely identifying role, singling out the thing in the given situation.
At last we found a place where we could make a fire. - descriptive
The place where we could make a fire was not a lucky one. - restrictive
An attributive clause (referred to as relative clause, because it is introduced by relative pronouns and adverbs) tells us which person or thing (or what kind of person or thing) the speaker means. The connective, which introduces the attributive clause, depends on the semantics of the word it describes: if it describes a person, it is introduced by the pronouns who, that or whose – A widow is a woman whose husbans died, a thing – that or which – I didn’t get the job (that, which) I applied for, a place – where – A cemetery is a place where people are buried, “the reason” – why, that or asyndetically – The reason (why, that) the plane couldn’t land was the storm, time (“the day”, “the last time”) – that or asyndetically – Do you remember the day (that) we met?.
Among the descriptive clauses there are those giving additional characteristics of the substantive referent and additional information about it: We decided not to swim in the sea, which looked rather dirty. These extra information descriptive clauses are separated by commas, we can’t use conjunction “that” in them, and the connective can’t be ommitted: My sister, who you once met, is visiting us next week. In some cases it is for the author to decide whether this clause is that of indispencible or extra information, which is shown in the oral form by intonation, and in the written form – by the use of commas. The new stadium(,) which holds 50 thousand people(,) will be opened next month.
Some descriptive attributive clauses have the whole of the main clause as the substantive referent. In this case they are also separated by commas: The weather was very good, which we hadn’t expected.
A subordinate clause is analogous to that of an attribute in a simple sentence. It differs from an attribute in so far as it characterises the thing denoted by its head word through some other action or situation in which that thing is involved. This could not, in many cases at least, be achieved within the limits of a simple sentence. Compare, for example, the sentence By October Isabelle was settled in the house where, she intended, she would live until she died. The clause where ... she would live with the dependent clause until she died contains information which could not be compressed into an attributive phrase within a simple sentence.
The question about the place of an attributive clause deserves a few remarks. Most usually, of course, an attributive clause comes immediately after its head word. This is too common to need illustration. But that is by no means an absolute rule. Sometimes an attributive clause will come, not immediately after its head word, but after some other word or phrase, not containing a noun. This is the case, for instance, in the following sentence: He wanted Ann to die, whom his son passionately loved, whom he had himself once come near to loving. The intervening infinitive to die, coming between the attributive clauses and their head word Ann, does not in any way impede the connection between them.
A different kind of separation is found in the following sentence: Jeremy saw the scene breaking upon him that he had dreaded all day and he felt no energy to withstand it. The subordinate clause that he had dreaded all day has the noun scene as its head word. Now this noun forms part of the complex object the scene breaking upon him. No ambiguity is created by the separation, as the subordinate clause cannot possibly refer to the pronoun him, and there is no noun between scene and the subordinate clause. That the word that is the relative pronoun and not the conjunction, is seen from the fact that dreaded, being a transitive verb, has no object coming after it; that the phrase all day is not an object is obvious because if the thing denoted by it were thought of as the object of the action the phrase must have been all the day.
With reference to adverbial clauses a question arises that is not always easy to answer, namely: whether they modify some part of the main clause or the main clause as a whole. The answer may prove to be different for different types of adverbial clauses and the question will have to be considered for each type separately. The criteria to be applied in settling this question have, however (at least partly), to be stated in advance.
We will first try out a method that has proved valid, on the whole, for determining whether a clause is an object clause or not. It will serve both for finding whether a clause is an adverbial clause or not, and if it is one, what it modifies. The method consists in dropping the clause in question and finding out what has been lost by dropping it and what part of the main clause has been affected by the omission (it may be the whole of the main clause). If this method does not yield satisfactory results in some particular case we will think of possible other ways of ascertaining the function of the subordinate clause.
The conjunctions introducing adverbial subordinate clauses are numerous and differ from each other in the degree of definiteness of meaning. While some of them have a narrow meaning, so that, seeing the conjunction, we may be certain that the adverbial clause belongs to a certain type (for example, if the conjunction is because, there is no doubt that the adverbial clause is a clause of cause), other conjunctions have so wide a meaning that we cannot determine the type of adverbial clause by having a look at the con-junction alone: thus, the conjunction as may introduce different types of clauses, and so can the conjunction while. With these conjunctions, other words in the sentence prove decisive in determining the type of adverbial clause introduced by the conjunction.