A complex sentence should consist of a main clause and subordinate clause. According to Oshima and Hogue (1991: 61), a complex sentence contains one independent clause and two or more dependent clauses. Furthermore, Werner and Church (1985: 177) state that complex sentence is the sentence that has a main clause and at least one dependent clause.
1. Independent Clause
Independent clause consists of a subject and predicate that expresses a complete idea. It is called as main clause and it can stand-alone.
For example:
When the telephone rang, I was still reading a book.
2. Dependent Clause
Dependent clause consists of a subject and predicate but it does not express a complete idea. It is one that is not complete but performs a single function in a sentence (Aronson, 1984: 137). It means that this clause cannot stand by itself.
For example:
When Marry gets home, she plans to relax for an hour.
Here, the underlined clause has a noun and a verb, but it does not make sense until reader reads the entire sentence. It is being subordinate clause (dependent clause) because it cannot stand-alone by itself.
a. Functions of Dependent Clause
The idea that we found in the subordinate or dependent clause may perform some functions in the following:
- For description
For example:
The old man, who wears the glasses, lives in America.
- For expressing cause
For example:
Because the cost of education has been rising, many students have financial problems.
- For stating purpose or reason
For example:
John has saved his salary for three years so he could buy a new house.
- For describing the conditions or circumstances
For example:
If Ahmad finished his work, he will go to the wedding party.
- For expressing time relationships
For example:
I am playing guitar while Marry is singing.
Oshima and Hogue (1991: 162) add that there are three kinds of dependent clauses used in a complex sentence. They are as follows:
- A dependent adverb clause
It begins with an adverbial subordinate such as when, while, because, even though, although, so that, and if. The position of this clause can be found after or before an independent clause. If it is found before an independent clause, it should followed by a comma. And if it is found after an independent clause, no comma is used.
For example:
- A dependent adjective (relative) clause
This clause begins with a relative pronoun such as who, whom, which, whose, or the relative adverb such as where, when, and why. It has function as adjective; that is, it modifies a noun.
For example:
Marni who is unsocial person called her lecturer.
- A dependent noun clause
This clause begins with that, whether, and sometimes with if. Here, a noun clause has function as noun; that is, it can be a subject or an object of the independent clause.
For example:
Based on the types of this dependent, McWhorter (1986: 62) states that the key idea is not obvious in long complex sentence. In this case, the students need to think about who or what the sentence is about and what is happening in the sentence in order to find a key idea.
For Example:
Burger World, which operates some 2000 fast food restaurants, plans to start working this spring, or at latest by early summer, on a new self-service restaurant in Rochester, New York, which is designed to test many new ideas in energy saving and customer convenience.
From this example, the answer for “Who and what is the sentence is about?” is Burger World. And, the answer for “What is happening in the sentence?” is plans.
To figure out what an author is trying to express in their sentences, a reader needs to know in which each sentence has a subject and a predicate but may have a compound subject and predicate and may be combined in a variety of ways with other sentences to form compound sentences or complex sentence with adjective, adverb, or noun clauses. It is supported by Devine (1989: 189). He states that students who have some knowledge of the ways the writers put their information and ideas into sentences are in a better position to process those sentences rather than the students who do not. Then, Statman (1980: 16) states that without the ability to isolate the different parts of the sentence into meaningful units even a good advanced learner may have great difficulties in extracting meaning from a long complex sentence. It means that, a reader has to be able to determine which one is main idea, compliment or additional information from what he reads.
Pearson and Johnson (1995: 16) say that longer sentences and more complex sentences tend to appear in passages that people have difficulty to understand. It means that, in understanding a long complex sentence, a reader should find the main clause. The idea of the main clause or independent clause is more important than the idea in subordinate clause or dependent clause. So, to be able to comprehend a long complex sentence, there are several ways need to be taken into account (Devine, 1989: 190):
- What is a writer talking about in this sentence?
- What seem to be his subject?
- What is he saying about his subject?
- What words and phrases the students can eliminate and still get the basic idea?
- How can the students cut this sentence up into several shorter sentences?
- How might the students say this sentence in their own?
