REVIEW OF RELATED LITERATURE
A. Theoretical Description
1. Conditional Sentences
Thomson and Martinet (1986: 196) said that “conditional sentences have two parts: the if-clause and the main clause.” It means that conditional sentences are complex sentences that consist of two clauses which are a main clause and a subordinate clause. The subordinate clause latter typically begins with the adverbial subordinator if.
a. Types of Conditional Sentences
Thompson and Martinet (1986: 197) said that conditional sentences have three types. Each type contains a different pair of tenses. There are three types of conditional sentences and each type has different pattern and meaning. Besides, there are other types of conditional sentences. Graver (1984: 88) stated that there
12 are four commonest and the most useful types of conditional sentences and those are types 0, 1, 2, and 3. Furthermore, Alexander (1994: 212) also stated that there is another type of conditional sentences beside those four types of conditional sentences. He said that “we do not always have to stick rigidly to the ‘three types of conditional sentences’ because there are occasions when we can use any tenses in if clauses, depending on the context.”
1) Conditional sentences type 0
Conditional sentences type 0 is used in “factual discussions or explanatory (particular scientific and technical) material” (Graver, 1984: 82). The fact of this type is true because it talks about the factual condition. The tenses used in both conditional and main clauses are the same. It can use simple present tense and also simple past tense.
2) Conditional Sentences type 1
Conditional sentences type 1 expresses something which can be true in present or future. There is possibility to be truth in the future if in the present it is not true. Azar (1989: 347) also gives the pattern of the conditional sentences type 1.
3) Conditional sentences type 2
Conditional sentences type 2 expresses something which is untrue in present or future. It means that the sentences in this type show the action which happen at that time, but they are only imagination. The real condition is contradictory with the expected condition, so the sentences are impossible. In this study, the “to be” used in this type is “were” because “was” is used in very
informal speech but it is not generally considered grammatically acceptable (Azar, 1989: 348).
4) Conditional sentences type 3
Conditional sentences type 3 expresses something which has happened in the past and it is not true or it does not happen in the past. In this type, the sentences show that the action happened in the past and the “if clause” shows the impossible things in the past.
5) Mixed conditionals
Beside those three types which are usually used, there is mixed conditionals. It is called mixed conditional because it uses mixed tenses in conditional sentences. Alexander (1994: 212) stated that “we do not always have to rigidly to the three types of conditional sentences because there are occasions when we can use any tenses in “if clauses”, depending on the context.”
b. Grammatical Changes
This part discusses the grammatical changes in conditional sentences. This part will be divided into three such as tense, modal auxiliary, general truth, and connectors. Those parts will discuss clearly and specifically about the tenses, modal auxiliary and the general truth in conditional sentences which are discussed in this study.
1) Tense
In conditional sentence type 1, there is no change. All the sentences use the simple form, both the main clause and the “if clause.” On the other hand, there
14 are changes in types 2 and 3 of conditional sentences. The changes in types 2 and 3 follow these rules.
a) Type 0
Conditional sentence type 0 shows the factual conditions which means that the fact is true. The tenses used in this type both in the conditional and main clauses are the same (Graver, 1994: 212). The tenses used in this type can be in simple present tense and simple past tense.
b) Type 1
Conditional sentence type 1 shows the actions which happen at that time and the “if clause” show the possible thing which happen or will happen.
Moreover, the tense which is used in this type is simple form. When the if-clause uses the simple present, the main clause uses the simple present future (Azar, 1989: 347).
c) Type 2
Conditional sentence type 2 shows the actions which happen at that time, but it tells about the impossible things in the present or future. In type 2, the tenses which are used in the main clause and in the if-clause are different. When the “if-clause” uses the simple past, the main clause uses simple past future.
d) Type 3
Conditional sentences type 3 shows the action which happened in the past and also tells about the impossible things in the past. In this type the tenses which are used in the main clause and in the “if clause” are also different. When the “if-clause” uses past perfect, the main clause uses past future perfect.
Azar summarized those types and the short explanations about their pattern and meaning in Table 2.1.
Table 2.1: Summary of Basic Verb Form Usage in Conditional Sentences (Azar, 1989: 347) MEANING conditional sentences used in the sentences. We can see the examples as follow.
(1) If I am as clever as you say I am, I would have been rich by now. Type 1+3 (2) If you knew me better, you wouldn’t have said that. Type 2+3 (3) If I had had your advantages, I’d be better off now. Type 3+2
16 Besides, there are the differences between the tenses which are used in conditional sentences and the fact. In conditional sentences type 1, there is no change. Both the conditional sentences and the fact use the simple present. On the contrary, types 1 and 2 have different tenses between the tense in conditional sentences and fact. The differences are as follow.
a) If the fact is in the present, the conditional sentence uses the past form.
b) If the fact is in the past, the conditional sentence uses the past perfect form.